SPG MITTEILUNGEN COMMUNICATIONS DE LA SSP · 16. Juni 2011 Procès-verbal de l'assemblée générale du 16 juin 2011 2. Kurzer Bericht des Präsidenten Bref rapport du président

Nr. 37Mai 2012

SPG MITTEILUNGENCOMMUNICATIONS DE LA SSP

Annual Meeting of theSwiSS PhySical Society

June 21 - 22, 2012 , ETH Zürich

General information: page 11, preliminary program: page 15

Im vergangenen Herbst erhielt Martin Gutzwiller den Doktor honoris causa der Universität Freiburg; ein willkommener An-lass für die SPG, die wissenschaftlichen Verdienste dieses grossen Schweizer Phy-sikers zu würdigen. Ab S. 34 berichten wir über Gutzwillers grundlegende Arbeiten auf den Gebieten des Quantenchaos und der korrelierten Elektronen.

The location of this year's annual meeting on the Hönggerberg Campus.Picture © Ralph Bensberg/ETH Zürich

The interesting relation between Albert Einstein and Georges Lemaître, two pio-neers of modern cosmology, is adressed in the article "From Static to Expanding Mod-els of the Universe" on page 43.

Public lectures

The program of this year's annual meeting includes two public highlights:

Nobel laureate Samuel C. C. Ting (CERN & MIT) will talk about space-borne detectors for cosmic rays, a key technology worth mentioning at the centen-nial of the discovery of cosmic rays.

Gebhard F. X. Schertler (ETH Zürich & PSI) will explain in a public tutorial about "Ultrafast Biology" (organised by NCCR MUST and ETH FAST), how experiments at the SwissFEL will help to better understand biological pro-cesses.

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SPG Mitteilungen Nr. 37

Inhalt - Contenu - ContentsJahrestagung der SPG in Zürich, 21. - 22. Juni 2012 - Réunion annuelle de la SSP à Zürich, 21 - 22 juin 2012 3

Vorwort - Avant-propos 3Preisverleihung und Generalversammlung 2012 - Cérémonie de remise des prix et assemblée générale 2012 3Statistik - Statistique 4Jahresbericht des Präsidenten - Rapport annuel du président 5Protokoll der Generalversammlung 2011 in Lausanne - Protocole de l'assemblée générale 2011 à Lausanne 5Jahresrechnung 2011 - Bilan annuel 2011 7Anpassung der Statuten - Modification des statuts 9Neue Sektion und Kommission - Nouvelle section et commission 10Allgemeine Tagungsinformationen - Informations générales sur la réunion 11Vorläufige Programmübersicht - Résumé préliminaire du programme 15Aussteller - Exposants 27

Kurzmitteilungen 27Progress in Physics (28): SATW Forum "Advanced Optoceramics" 28Progress in Physics (29): Understanding exchange bias in thin films 30The legacy of Martin Gutzwiller 34

Martin Gutzwiller and his periodic orbits 34Martin Gutzwiller and his wave function 37

Physik und Gesellschaft: "Lead-User-Workshops" für effizientes Innovations- & Produktvariantenmanagement 41History of Physics (4): From Static to Expanding Models of the Universe 43Über den Einfluss des Lichtes auf den Menschen 47

Nicht-visuelle Lichtwirkungen beim Menschen 47Lighting Application for Non-Visual Effects of Light 49

Präsident / PrésidentDr. Christophe Rossel, IBM Rüschlikon, [email protected]

Vize-Präsident / Vice-PrésidentDr. Andreas Schopper, CERN, [email protected]

Sekretär / SecrétaireDr. MER Antoine Pochelon, EPFL-CRPP, [email protected]

Kassier / TrésorierDr. Pierangelo Gröning, EMPA Thun, [email protected]

Kondensierte Materie / Matière Condensée (KOND)Dr. Urs Staub, PSI, [email protected]

Angewandte Physik / Physique Appliquée (ANDO)Dr. Ivo Furno, EPFL-CRPP, [email protected]

Astrophysik, Kern- und Teilchenphysik /Astrophysique, physique nucléaire et corp. (TASK)Prof. Martin Pohl, Uni Genève, [email protected]

Theoretische Physik / Physique Théorique (THEO)Prof. Gian Michele Graf, ETH Zürich (ad interim), [email protected]

Physik in der Industrie / Physique dans l‘industrieDr. Kai Hencken, ABB Dättwil, [email protected]

Atomphysik und Quantenoptik /Physique Atomique et Optique QuantiqueProf. Antoine Weis, Uni Fribourg, [email protected]

Physikausbildung und -förderung /Education et encouragement à la physiqueDr. Tibor Gyalog, Uni Basel, [email protected]

Geschichte der Physik / Histoire de la PhysiqueProf. Jan Lacki, Uni Genève, [email protected]

SPG Administration / Administration de la SSP

Allgemeines Sekretariat (Mitgliederverwaltung, Webseite, Druck, Versand, Redaktion Bul-

letin & SPG Mitteilungen) /Secrétariat générale (Service des membres, internet, impression, envoi, rédaction Bulletin

& Communications de la SSP)

S. Albietz, SPG Sekretariat, Departement Physik,Klingelbergstrasse 82, CH-4056 BaselTel. 061 / 267 36 86, Fax 061 / 267 37 84, [email protected]

Buchhaltung / Service de la comptabilitéF. Erkadoo, SPG Sekretariat, Departement Physik,Klingelbergstrasse 82, CH-4056 BaselTel. 061 / 267 37 50, Fax 061 / 267 13 49, [email protected]

Sekretärin des Präsidenten / Secrétaire du présidentSusanne Johner, [email protected]

Wissenschaftlicher Redakteur/ Rédacteur scientifiqueDr. Bernhard Braunecker, Braunecker Engineering GmbH,[email protected]

Vorstandsmitglieder der SPG / Membres du Comité de la SSP

Impressum:Die SPG Mitteilungen erscheinen ca. 2-4 mal jährlich und werden an alle Mitglieder abgegeben.

Abonnement für Nichtmitglieder:CHF 20.- pro Jahrgang (Inland; Ausland auf Anfrage), incl. Lieferung der Hefte sofort nach Erscheinen frei Haus. Bestellungen bzw. Kündigungen jeweils zum Jahresende senden Sie bitte formlos an folgende Adresse:

Verlag und Redaktion:Schweizerische Physikalische Gesellschaft, Klingelbergstr. 82, CH-4056 Basel, [email protected], www.sps.ch

Redaktionelle Beiträge und Inserate sind willkommen, bitte wenden Sie sich an die obige Adresse.Namentlich gekennzeichnete Beiträge geben grundsätzlich die Meinungen der betreffenden Autoren wieder. Die SPG übernimmt hier-für keine Verantwortung.

Druck:Werner Druck AG, Kanonengasse 32, 4001 Basel

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Communications de la SSP No. 37

Jahrestagung der SPG in Zürich, 21. - 22. Juni 2012Réunion annuelle de la SSP à Zürich, 21 - 22 juin 2012

Vorwort

Die erfolgreichen Tagungen der letzten Jahre haben gezeigt, daß die SPG auf dem richtigen Pfad ist. Sowohl die Betei-ligung der verschiedenen NCCRs alle 2 Jahre, als auch die Kooperation mit unseren österreichischen Nachbarn erlau-ben eine exzellente Vernetzung und den Austausch über Fachbereichs- und Landesgrenzen hinweg. Nicht zuletzt die Zusammenarbeit mit Fachgesellschaften, die einen starken Bezug zur Physik haben, erlaubt auch immer wie-der den Blick über den Tellerrand des eigenen Wirkens.

In diesem Jahr ist z.B. das 100jährige Jubiläum der Entde-ckung der Röntgenbeugung durch Max von Laue Anlaß für die Schweizerische Gesellschaft für Kristallographie (SGK), sich mit einer Sitzung an unserer Tagung zu beteiligen.Der Einbezug von lange vernachlässigten Fachgebieten ist ebenfalls geglückt, wie z.B. die nun bereits fest etablierte Sitzung zur Geschichte der Physik zeigt. Die letztjährige Sit-zung zur Geophysik gibt sogar Anlaß, das Gebiet in diesem Jahr in einen erweiterten Rahmen unter "Physik der Erde, Atmosphäre und Umwelt" einzubetten und eine gleichna-mige Sektion zu gründen.

Im folgenden finden Sie die wichtigsten Tagungsinformati-onen sowie eine vorläufige Programmübersicht. Das defi-nitive Programm wird in Kürze auf der SPG-Webseite ver-fügbar sein.

In diesem Sinne hoffen wir auf eine rege Beteiligung an der diesjährigen Tagung und freuen uns auf Ihren Besuch.

Avant-propos

Le succès des réunions des années dernières a démontré que la SSP est sur la bonne voie. Autant la participation des différents NCCRs tous les deux ans que notre coopération avec nos voisins autrichiens, favorisent le développment d’un excellent réseau et l’échange au delà des spécialités et des frontières. La collaboration avec les sociétés savantes qui ont un fort lien avec la physique, permet aussi de jeter régulièrement un coup d’oeil sur les domaines adjacents à nos propres activités.

Cette année, la célébration du centenaire de la décou-verte de la diffraction des rayons X par Max von Laue, est l’occasion pour la Société Suisse de Crystallographie de participer avec une session à notre réunion annuelle.L’incorporation de domaines longtemps négligés est tout aussi réussie, tel que le montre par ex. la session désor-mais solidement établie sur l’Histoire de la Physique. La séance sur la Géophysique de l’année dernière nous a incité à élargir le sujet vers la "Physique du Globe et de l’Environnement", et à fonder une nouvelle section du même nom.

Dans les pages suivantes vous trouverez les informations essentielles sur la conférence ainsi que le programme pro-visoire. La version finale sera prochainement accessible sur notre site internet.

Nous comptons donc sur une participation active et nom-breuse à notre réunion annuelle et nous réjouissons de vo-tre visite.

Preisverleihung und Generalversammlung 2012 -Cérémonie de remise des prix et assemblée générale 2012

Donnerstag 21. Juni 2012, 11:30h - Jeudi 21 juin 2012, 11:30h

ETH Zürich, Hönggerberg, Gebäude HPH, Hörsaal G 1

11:30 Preisverleihung Cérémonie de remise des prix

11:50 Generalversammlung Assemblée générale

1. Protokoll der Generalversammlung vom16. Juni 2011

Procès-verbal de l'assemblée générale du 16 juin 2011

2. Kurzer Bericht des Präsidenten Bref rapport du président3. Rechnung 2011, Revisorenbericht Bilan 2011, rapport des vérificateurs des

comptes4. Anpassung der Statuten Modification des statuts5. Neue Sektion und Kommission Nouvelle section et commission6. Projekte Projets7. Wahlen Elections8. Diverses Divers

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Neue Mitglieder 2011 -Nouveaux membres en 2011

Allenspach Rolf, Ammann Stephan, Anabitarte Miguel, An-dritsch Florian, Balzan Riccardo, Becker Henrik, Bednorz J. Georg, Birrer Simon, Boillat Bénédicte, Boss Jens Mi-chael, Bräm Beat, Braitsch Daniel, Braun Johannes, Büchel Samuel, Bunk Oliver, Capelli Achille, Cedzich Christopher, Chang Johan, Chopdekar Rajesh Vilas, Chowdhuri Zema, Christandl Matthias, Ciganovic Nikola, Conrad Roberta, Da-hinden Fabienne, Debus Pascal, Diebold Andreas, Donner Tobias, Eggenschwiler Federico, Ehrbar Stefanie, El Bak-kali Issam, El Moussaoui Souliman, Falke Johannes, Flöry Nikolaus, Flühmann Christa, Gauvin Neal, Gehrig Jeffrey, Gehrmann-De Ridder Aude, Gersdorf Thomas, Göldi Da-mian, Gomes Gerber Isabel, Grimm Alexander, Häberli Flo-rian, Hälg Sebastian, Häusler Samuel, Herrmann Andreas, Howald Ludovic, Huber Felix, Iacobucci Giuseppe, Imamo-glu Atac, Jenatsch Sandra, Jochum Johanna, Jusufi Abas, Kambly Dania, Kamleitner Josef, Kangeldi Selim, Kasprzak Malgorzata, Keller Stefan, Khaw Kim Siang, Kläui Mathias, Klauser Christine, Kobayashi Masaki, Korppi Maria, Kouli-alias Dimitrios, Krempasky Juraj, Kreslo Igor, Kwuida-Man-they Katarina, Leimer Pascal, Löffler Jörg F., Lüthi Florian, Maetz Marc, Maghrbi Yasser, Marsik Premysl, Minkowski Peter, Mirzaei Seyed Imam, Mokso Rajmund, Moser Chri-stophe, Nicola Andrina, Oberle Markus, Ockeloen Caspar, Orsi Silvio, Pagani Kurt, Papariello Luca, Parrinello Michele, Patthey Luc, Pavuna Davor, Pfefferle David, Piamonteze Cinthia, Pikulski Marek, Pilet Nicolas, Plumb Nicholas, Prsa Krunoslav, Radovic Milan, Reichert Julia, Riedo Andreas, Rocco Gaudenzi, Rodriguez Alvarez José, Rose Ruben, Ruffieux Silvia, Rutar Giada, Schäfer Vera, Schmidt Alexan-der, Schnoz Sebastian, Schönherr Peggy, Schopper Andre-as, Schulthess Thomas, Schumann Marc, Sehner Michael, Seidel Mike, Sellerio Alessandro Luigi, Shiroka Toni, Stamm Christian, Stelzer Carol, Stöckl Quirin S., Timpu Flavia Claudia, Tortschanoff Andreas, Tschirky Thomas, Verzetti Mauro, Viereck Julian, von Baussnern Samuel, Wacker Kay, Wágner Dávid, Wallny Rainer, Walt Roger, Waltar Kay, Ward Simon, Watts Benjamin, Weigele Pirmin, Wenzler Dominic, Wertnik Melina, Winkler János, Winterhalter Carla, Wittwer Peter, Witzemann Amadeus, Yarar Hevjin, Zai Anja

Ehrenmitglieder - Membres d'honneur

Prof. Hans Beck (2010)Dr. J. Georg Bednorz (2011)Prof. Jean-Pierre Blaser (1990)Prof. Jean-Pierre Borel (2001)Prof. Jean-Pierre Eckmann (2011)Prof. Charles P. Enz (2005)Prof. Øystein Fischer (2010)Prof. Hans Frauenfelder (2001)Prof. Jürg Fröhlich (2011)Prof. Hermann Grunder (2001)Prof. Hans-Joachim Güntherodt (2010)Dr. Martin Huber (2011)Prof. Verena Meyer (2001)

Prof. K. Alex Müller (1991)Prof. Hans Rudolf Ott (2005)Prof. T. Maurice Rice (2010)Dr. Heinrich Rohrer (1990)Prof. Louis Schlapbach (2010)

Assoziierte Mitglieder - Membres associés

A) Firmen• F. Hoffmann-La-Roche AG, 4070 Basel• Oerlikon Leybold Vacuum Schweiz AG, 8050 Zürich

B) Universitäten, Institute• Albert-Einstein-Center for Fundamental Physics, Uni-

versität Bern, 3012 Bern• Département de Physique, Université de Fribourg,

1700 Fribourg• Departement Physik, Universität Basel, 4056 Basel• Departement Physik, ETH Zürich, 8093 Zürich• EMPA, 8600 Dübendorf• Lab. de Physique des Hautes Energies (LPHE), EPFL,

1015 Lausanne• Paul Scherrer Institut, 5332 Villigen PSI• Physik-Institut, Universität Zürich, 8057 Zürich• Section de Physique, Université de Genève, 1211 Ge-

nève 4

C) Studentenfachvereine• AEP - Association des Etudiant(e)s en Physique, Uni-

versité de Genève, 1211 Genève 4• Fachschaft Physik und Astronomie, Universität Bern,

3012 Bern• Fachschaft Physique, Université de Fribourg, 1700 Fri-

bourg• Fachverein Physik der Universität Zürich (FPU),

8057 Zürich• FG 14 (Fachgruppe für Physik-, Mathematik- und Versi-

cherungswissenschaft), Universität Basel, 4056 Basel• Les Irrotationnels, EPFL, 1015 Lausanne• Verein der Mathematik- und Physikstudierenden an

der ETH Zürich (VMP), 8092 Zürich

Verteilung der Mitgliedskategorien -Répartition des catégories de membres

(31.12.2011)

Ordentliche Mitglieder 697 Doktoranden 37 Studenten 78 Doppelmitglieder DPG, ÖPG oder APS 193 Doppelmitglieder PGZ 38 Mitglieder auf Lebenszeit 150 Assoziierte Mitglieder 16 Bibliotheksmitglieder 2 Ehrenmitglieder 18 Beitragsfreie (Korrespondenz) 10

Total 1239

Statistik - Statistique

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Jahresbericht 2011 des Präsidenten - Rapport annuel 2011 du présidentOnce again, one of the highlights of 2011 for the SPS was its successful annual meeting organized at the EPFL in Lausanne on 15-17 June 2011, jointly with the Austrian Physical Society (ÖPG), and both national societies of As-tronomy and Astrophysics (SSAA and ÖGAA). It was very well attended with about 650 participants, 10 plenary talks, 470 contributions spread over 10 parallel sessions and one large poster session. The commercial exhibitions reached a record number of 22 company booths. One can claim without any doubt that the formula of having our meeting every other year with our Austrian colleagues is a success. The meeting 2013 is therefore already planned in Vienna for early September.The organization of the alternating meetings with the Swiss NCCRs and other invited learned societies has also pro-ven to be an excellent and appreciated means to make this event attractive to the Swiss community. A detailed review of the meeting 2011 was published in the SPS Communi-cations No 35 and on our website.Worth remembering is the celebration of the centennial of the discovery of superconductivity with dedicated talks, a lively round table in presence of the two Nobel Laureates K. A. Müller and J. G. Bednorz and a special exhibition.

Based on the success of the session on Geophysics, it was proposed to create a new section named "Earth, Atmos-phere and Environmental Physics". A dedicated session on this topic is planned in our next annual meeting at the ETHZ on 21-22 June 2012 (see page 10 in this issue for details).

During the joint award ceremony the three SPS awards as well as several prizes of the ÖPG were attributed. During this ceremony the honorary membership was conferred to four new members.At the General Assembly, two new board members have been elected; several others have been reelected (see mi-nutes on the next page).

It is with pleasure that the SPS endorsed also the new membership of CHIPP, the Swiss Institute of Particle Phy-sics, presided by Martin Pohl, within SCNAT. It trusts that this sister organization will strengthen science in general and physics in particular in association with the SPS.

The number of individual members keeps increasing steadi-ly with about 1250 by the end of 2011. This enjoyable trend goes in parallel with the strong increase of collective mem-bers - renamed ‘associate’ members in the future - found among the different departments of physics, research orga-nizations and physics student associations.

Because of improved financial incomes (membership, exhi-bition) but also because of stronger control of our expenses (reduction of publication and mailing costs) the negative trend of the last three years has been stopped and our bud-get 2011 ended again in the black with a slight earning.

Thanks to the excellent work of our scientific editor B. Braunecker, the SPS Bulletin continues to be a valuable source of information with society news, and the now well established topical rubriques 'Progress in Physics', 'Phy-sics and Society' and 'Physics Anecdotes'.

In our collaboration with the Physikalische Gesellschaft Zu-rich (PGZ), a joint Symposium on "Careers for Physicists" was organized on the 25 October 2011. The student asso-ciations of the SPS Young Physicists Forum (YPF), VMP (ETHZ), FPU (Uni. Zürich) and FG14 (Uni. Basel) participa-ted in this successful symposium. In fact the YPF remains active and continues to organize special events, such as visits of research centers or institutes for its student mem-bers.

In a well established tradition, the SPS sponsored also the Swiss Physics Olympiads and the Swiss Young Physicists Tournament in their respective activities. The best male and female finalists of the SwissPhO were awarded with SPS prizes (http://www.swisspho.ch/en/winners2011).

The SPS is actively represented via its president or other members in different EPS groups and commissions, in par-ticular the editorial board of Europhysics News, Europhy-sics Letters, the Forum Physics and Society, the Techno-logy group and the Energy group. The meeting of the latter took place at the Akershus Energy Park, close to Oslo on 6-7 October 2011. In addition to energy issues specific to Norway (hydro-energy, Thorium reactors), reports on radio-active waste disposal techniques and the status of dispo-sals in EU nuclear energy countries including Switzerland (Nagra) were presented.As a member organization of the Swiss Academy of Sci-ence SCNAT, the SPS is part of the platform Mathematics, Astronomy and Physics. We acknowledge here the orga-nizational and financial support of SCNAT in the pursuit of our tasks and activities. The support of the Swiss Academy of Engineering Science SATW is also acknowledged and hopefully our interaction will be further developed on im-portant issues such as energy, resources and sustainability, information technology, nanotechnology, education as well as the training of the physicists in industry and academia.

Christophe Rossel, President, March 2012

Protokoll der Generalversammlung vom 16.06.2011 in LausanneProtocole de l'assemblée générale du 16.06.2011 à Lausanne

Traktanden1. Protokoll der Generalversammlung vom 22.6.20102. Bericht des Präsidenten3. Rechnung 2010 & Revisorenbericht4. Wahlen5. Projekte6. Diverses

Der Präsident, Christophe Rossel, eröffnet die Generalver-sammlung um 12:10 Uhr. Anwesend sind 31 Mitglieder.

1. Protokoll der Generalversammlung vom 22.6.2010Das Protokoll der letzten Generalversammlung in Basel wird kommentarlos genehmigt.

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2. Bericht des PräsidentenAuf Seite 5 der „SPG Mitteilungen Nr. 34“ wurde der Jah-resbericht des Präsidenten bereits veröffentlicht.

• Zur Jahrestagung vom 21.-22. Juni 2010 in Basel mit NCCR ManEP, NANO, QP, CCMX, POLYCOLL (SCG) ka-men rund 500 Teilnehmer und 17 Aussteller.

• An der Generalversammlung 2010 wurden fünf neue Eh-renmitglieder ernannt: Profs. H. Beck, O. Fischer, H.-J. Güntherodt, T. M. Rice, L. Schlapbach.

• Die GV 2010 schuf neue Mitgliederkategorien und passte sowohl die Statuten an, wie teilweise auch die seit acht Jahren unveränderten Mitgliederbeiträge.

• Als Werbeaktion erhielten alle Schweizer Physikprofes-soren den neuen SPG-Flyer zum Verteilen an die Studie-renden.

• Folgende Institutionen konnten als Kollektivmitglieder gewonnen werden: Die Physik-Departemente der Uni-versitäten Basel, Genf und Zürich, der ETH Zürich, das LPHE der EPF Lausanne sowie die Studentenvereine VMP (ETHZ), FPU (Uni ZH), AEP (Uni Genf).

Der Präsident informiert die Anwesenden, dass der Vor-stand die missverständliche Bezeichnung "Kollektivmit-gliedschaft" durch "Assoziierte Mitgliedschaft" ersetzen möchte. Die erforderliche Statutenänderung wird näch-stes Jahr auf die Traktandenliste gesetzt und der GV 2012 zur Abstimmung vorgelegt.

• Die dreimal jährlich erscheinenden "SPG Mitteilungen" werden noch interessanter: Zu den bisherigen Rubriken "Fortschritt in der Physik", "Physik & Gesellschaft" und "Physik-Anekdoten" kommt die neue Serie "Geschichte der Physik".

Besondere Anlässe im vergangenen Vereinsjahr waren:• Öffentlicher, von SPS und PGZ gemeinsam organisierter

Anlass "DIE WISSENSEXPLOSION – Chancen und Ri-siken – Wissenschaftskommunikation im Zeitalter elek-tronischer Medien", Sa. 02.10.2010, Uni Zürich.

• 50 Jahre Laser: Der Tanz der Photonen, vom 10.-12.06.2010 an der Universität Bern und vom 19.-20.11.2010 an der Universität Fribourg.

• Im Rahmen unseres neuen Young Physicists Forums (VMP) organisierte der VMP (Verein Mathematik- & Physik-Studierender der ETH Zürich) folgende gut be-suchte Exkursionen: PSI Villigen (4.5.2010), EPFL-CRPP (22.11.2010), ABB (18.4.2011) und IBM Research (30.5.2011).

• Als Sponsor der Schweiz. Physik-Olympiaden stiftet die SPG jeweils zwei Nachwuchspreise zu je CHF 500, wel-che der Präsident an der Schlussfeier vom 3.4.2011 in Aarau überreichte.

• Weiterhin ist die SPG Sponsor des Swiss Young Physi-cists Tournament (PSI, April 2011) und des Schweizer Teams am International Young Physicists Tournament (Teheran, Juli 2011).

3. Rechnung 2010 & RevisorenberichtDer Kassier, Pierangelo Gröning, präsentiert die Jahres-rechnung 2010, die detailliert in den "SPG-Mitteilungen Nr. 34" veröffentlicht wurde. Sie schliesst mit einem Verlust von CHF 25'777, bei einem Vereinsvermögen per 31.12.2010 von CHF 19'406.50.

Nachdem der Revisorenbericht vorgelesen worden ist, stimmt die Generalversammlung der Jahresrechnung 2010 und der Entlastung des Vorstands zu.

4. WahlenDer Präsident dankt den beiden ausscheidenden Vor-standsmitgliedern für ihren Einsatz: Prof. Klaus Kirch, 6 Jahre Leiter der SPG-Sektion "Astro-, Kern- Teilchenphy-sik" und Prof. Ulrich Straumann, 2 Jahre Vize-Präsident der SPG.In corpore werden einstimmig neu resp. wieder gewählt:

• Vize-Präsident (neu): Dr. Andreas Schopper, CERN• Astro-, Kern- Teilchenphysik (neu): Prof. Martin Pohl,

Universität Genf• Atomphysik & Quantenoptik (bisher): Prof. Antoine Weis,

Universität Fribourg• Physik in der Industrie (bisher): Dr. Kai Hencken, ABB• Theoretische Physik (bisher): Prof. Dionys Baeriswyl,

Universität Fribourg• Angewandte Physik (bisher): Dr. Ivo Furno, EPFL• Physikausbildung & -förderung (bisher): Dr. Tibor Gya-

log, Universität Basel

5. Projekte• Das "Young Physicists Forum" wird mit den Studenten-

Fachschaften weitere Aktivitäten, Betriebsbesichti-gungen und Exkursionen für Studenten organisieren.

• Zusammen mit dem PGZ plant die SPG im September 2011 in Zürich ein Symposium über den Physiker-Beruf.

6. Diverses• An der letzten GV wünschte ein Mitglied, die SPG solle

dem Anglizismus entgegentreten und dafür sorgen, dass vermehrt deutschsprachige Beiträge gedruckt werden.

Der Vorstand hat das Anliegen diskutiert, sieht jedoch keinen Handlungsbedarf. Bei einem Mitgliedermagazin wie den "SPG Mitteilungen" muss in erster Linie der Inhalt stimmen – in welcher Sprache ist weniger wich-tig. Was andere Publikationen betrifft, kann und will der SPG-Vorstand keinen Einfluss auf redaktionelle Ent-scheide nehmen.

• Die nächste SPG-Jahrestagung wird am 21./22. Juni 2012 an der ETH Zürich stattfinden. Weitere Einzelheiten erscheinen demnächst auf der SPG-Internetseite (www.sps.ch).

Der Präsident dankt den Anwesenden für ihr Erscheinen sowie den Delegierten und seinen Vorstandskollegen für Ih-ren Einsatz und die gute Zusammenarbeit im vergangenen Amtsjahr.

Ende der Generalversammlung: 11:15 Uhr.

Lausanne, 16. Juni 2011Die Protokollführerin: Susanne Johner

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Jahresrechnung 2011 - Bilan annuel 2011

Aktiven PassivenUmlaufsvermögenPostscheckkonto 19233,53Bank - UBS 230-627945.M1U 12575,54Debitoren - Mitglieder 2017,50Debitoren - SCNAT/SATW u.a.m. 56851,00Transitorische Aktiven 1049,70

AnlagevermögenBeteiligung EP Letters 15840,00Mobilien 1,00

FremdkapitalMobiliar 1,00Mitglieder Lebenszeit 59824,50Transitorische Passiven 11135,90

EigenkapitalVerfügbares Vermögen 19406,51

Total Aktiven Passiven 107568,27 90367,91Gewinn 17200,36Total 107568,27 107568,27

Verfügbares Vermögen per 31.12.11 nach Gewinnzuweisung 36606,87

Bilanz per 31.12.2011

Aufwand ErtragGesellschaftsaufwandEPS - Membership 15634,30SCNAT - Membership 7903,00SATW-Mitgliederbeitrag 1750,00

SCNAT & SATW Verpflichtungskredite SPG-Jahrestagung 37766,26Schweizer Physik Olympiade 4000,00SPG Young Physicist's Forum 7133,15EGA-43 Kongress 2011, Fribourg 4000,00100 Jahre Supraleitung 11851,00SCNAT/SPG Bulletin 5500,00SCNAT Periodika (SPG-Mitteilungen, Druckkosten) 19444,20SCNAT Int. Young Phys. Tournament 5500,00

BetriebsaufwandLöhne 11732,64Sozialleistungen 863,25Porti/Telefonspesen/WWW- und PC-Spesen 908,75Versand (Porti Massensendungen) 5334,00Unkosten 3130,30Büromaterial 321,60Bankspesen 163,00Debitorenverluste Mitglieder 1971,00Debitorenverlust SCNAT/SATW u.a.m. 5149,00Sekretariatsaufwand extern 9675,00

ErtragMitgliederbeiträge 87670,35Inserate/Flyerbeilagen SPG Mitteilungen 200,00Aussteller 24771,69Zinsertrag 125,90Ertrag aus EP Letters Beteiligung 2162,87

SCNAT & SATW Verpflichtungskredite SPG-Jahrestagung (SCNAT) 15000,00Schweizer Physik Olympiade 4000,00SPG Young Physicist's Forum 7000,00EGAS-43 Kongress 2011, Fribourg 4000,00100 Jahre Supraleitung 12000,00SATW, 100 Jahre Tieftemperatur und Supraleitung/Session Géophysique 5000,00SPG Bulletin (SCNAT) 5500,00Periodika (SPG-Mitteilungen, Druckkosten) (SCNAT) 4000,00SCNAT Int. Young Phys. Tournament 5500,00

Total Aufwand/Ertrag 159730,45 176930,81Gewinn 17200,36Total 176930,81 176930,81

Erfolgsrechnung per 31.12.2011

8


F. Erkadoo, SPG Büro, Departement Physik, Klingelbergstrasse 82, CH-4056 Basel

Tel : 061 / 267 37 50, Fax : 061 / 267 13 49, Email : [email protected]

Revisorenbericht zur Jahresrechnung 2011

Die Jahresrechnung 2011 der SPG wurde von den unterzeichneten Revisoren geprüft und mit den Belegen in Übereinstimmung befunden. Die Revisoren empfehlen der Generalversammlung der SPG, die Jahresrechnung zu genehmigen und den Kassier mit bestem Dank für die gute Rechnungsführung zu entlasten. Die Revisoren der SPG: Prof. Dr. Philipp Aebi Dr. Pascal Ruffieux Basel, 15. März 2012

9


Seit der letzten Änderung vor zwei Jahren ist der Vorstand auf zwei kleine Unschönheiten in den Statuten aufmerksam gemacht worden. Diese betreffen den Begriff "Kollektivmit-glieder", der verschiedentlich zu Mißverständnissen geführt hat. Ferner wird die Definition der Kollektivmitglieder Grup-pe B als zu eng gefasst angesehen, da z.B. eine überstaat-liche Organisation wie das CERN danach nicht Mitglied werden kann.

Es wird daher über die folgenden kleinen Änderungen ab-gestimmt:

- Der Begriff "Kollektivmitglieder" wird ersetzt durch "As-soziierte Mitglieder". Dies betrifft Artikel 2 und Anhang 1.

- Die Definition der Gruppe B in Artikel 2 wird erweitert.

Die bisherige Fassung der Statuten finden Sie auf www.sps.ch ->SPG ->Statuten.

Art. 2Die Gesellschaft besteht aus ordentlichen Mitgliedern, aus studentischen Mitgliedern (Studenten), aus Ehrenmitglie-dern und aus Assoziierten Mitgliedern.Als Studenten gelten Personen, welche an einer Universi-tät immatrikuliert sind und noch keinen Diplom-/Masterab-schluß haben.

Assoziierte Mitglieder werden in folgende Gruppen einge-teilt:

A) FirmenB) Universitäten bzw. deren Untereinheiten (z.B. Insti-

tute, Forschungslabore) oder anerkannte staatliche, überstaatliche bzw. internationale Forschungseinrich-tungen

C) Studentenorganisationen / Fachgruppen an Schwei-zer Hochschulen

[...]

Art. 24Die gegenwärtige Version der Statuten der Schweize-rischen Physikalischen Gesellschaft wurde an der Gene-ralversammlung vom 21. Juni 2012 in Zürich angenommen. Sie annulliert alle vorherigen Bestimmungen.

Après les dernières modifications d'il y a deux ans, le co-mité a été rendu attentif à deux petites imprécisions dans les statuts. Elles concernent le terme de 'membre collectif' qui a conduit à quelques malentendus. De plus la définition du groupe B des membres collectifs est considérée comme trop limitée. Ainsi une organisation internationale comme le CERN ne pourrait pas devenir membre de la SSP.

Pour ces raisons il sera nécéssaire de se prononcer sur les petits amendements suivants:

- le terme "membres collectifs" est remplacé par "mem-bres associés" dans les Article 2 et Annexe 1.

- la définition du groupe B dans l'Article 2 est élargie.

La version actuelle des statuts se trouve sous www.sps.ch -> SSP -> Statuts.

Art. 2La Société se compose de membres ordinaires, de membres étudiants, de membres honoraires et de membres associés.

Comme étudiants sont considérées les personnes immatri-culées dans une université et qui n’ont pas encore obtenu de Diplôme ou Master.

Les membres associés se composent des groupes sui-vants:

A) Compagnies commercialesB) Universités et leurs unités (par ex. instituts, laboratoires

de recherche) ainsi que les institutions nationales, su-pranationales ou internationales de recherche.

C) Organisations ou associations d’étudiants liées à une université suisse

[...]

Art. 24La présente version des statuts de la Société Suisse de Physique a été adoptée par l’assemblée générale à Zürich, le 21 juin 2012. Elle annule toutes les dispositions anté-rieures.

Anpassung der Statuten - Modification des statuts

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10


Until now, the Young Physicists Forum (YPF) is a loose compound of nearly all Swiss physics students organiza-tions – namely the associations from École polytechnique fédérale de Lausanne, ETH Zürich, Uni Basel, Uni Bern, Uni Fribourg and Uni Genève.

Everything started at our first meeting in May 2011, where the representatives of the different students organizations agreed on the fact that there is a need for better connection amongst the physics students and between students and experienced physicists. To work out our aims and goals more precisely we started to meet regularly, each seme-ster at a different university, to force initially the exchange amongst our board members. Since our first meeting the SPS supported us and offered their help.

As a result of our efforts, the main goal of the YPF is to build up a network and encourage the exchange of information and experience amongst our students, but also with other physicists. This we want to reach e.g. by organizing joint events like visits of research institutions, companies etc. Starting to include the members of our associations, our web-forum was released in April 2012 and as a first event we plan to visit CERN this summer. To foster the communi-cation between our members and "real-life physicists" the SPS turns out to be the ideal platform as they already com-bine reasearch and industrial interests, covering all areas of physics. In addition the SPS offers a stable framework within which the YPF can develop and grow. After consul-

tation with the board of the SPS we think that all involved parties can profit if the YPF is formaly founded as a com-mission of the SPS.In a first step all participating students organizations joined the SPS as Associated Members. The next step is our for-mal application at the General Assembly at the SPS annual meeting in June 2012, to accept the YPF as a commission. If our inquiry is accepted, we see it as our responsibility to bring our students in contact with the SPS so they get an impression of the wide range of possibilities they will have when finishing their studies. Thus we want to spark interest of young physics students in the SPS as soon as possible. We are looking forward to a productive and successful co-operation and many new acquaintances.

List of YPF founding members:Les Irrotationnels, Association des étudiants en physique de l'EPFL, http://irrotationnels.epfl.chVerein der Mathematik- und Physikstudierenden an der ETH Zürich (VMP), www.vmp.ethz.chUni Basel, Fachgruppe 14 (FG 14), www.fg14.unibas.chUni Bern, Fachschaft Physik und Astronomie (FPA), http://www.fpa.unibe.chUni Fribourg, Fachschaft Physique (FPF)Uni Genève, Association des Etudiant(e)s en Physique (AEP), http://www.asso-etud.unige.ch/aep/

Julia Reichert and Talitha Weiss, YPF, Universität Basel

New Commission "Young Physicists Forum"

In 2012, the SPS starts up a new section, Earth, Atmos-phere and Environmental Physics, following formally the 2011 sessions on geophysics (From Planetary to Enginee-ring Geophysics).

Earth, atmosphere and environmental physics can be de-scribed in terms of the laws of physics. Examples include a number of environmental issues such as global warming, waste depositories, ozone layer depletion, energy crisis and renewable energy sources, air, soil and water pollution, etc.This section pays tribute to the emphasis placed on moni-toring and understanding processes, as well as predicting changes of our physical world. The underlying topics may be regarded as Earth- or geo-sciences oriented, being a particular combination of physical, chemical, and biologi-cal processes linking and determining every components of the Earth system on a wide variety of spatial and temporal scales.

Earth Physics encompasses a number of topics from the geophysics of the globe (plate tectonics, geomagnetism, solid state at high pressures, seismology, geodesy, cosmic

rays, extra-terrestrial geophysics,…) to engineering geo-physics, applied geophysics (analysis of geological resour-ces, of geomaterials, of geological hazards, of geological barriers for waste storage, monitoring of contaminated sites), aiming at a description from first principles.

Atmospheric Physics is concerned with the structure and evolution of the planetary atmospheres and with the wide range of phenomena that occur within them, with a particu-lar focus on the Earth’s atmosphere interacting with other components such as the lithosphere, the biosphere, the hy-drosphere and the cryosphere.

Environmental Physics involves the many aspects of phy-sics that pervade environmental processes in our everyday lives and in naturally occurring phenomena. This includes energy supply and resources issues, which growing needs and use can impact on environment. It aims at understan-ding the various links between topics such as, e.g.: su-stainability, contribution of renewable sources, efficiency, wastes and pollution, CO2, climatic impact.

New Section "Earth, Atmosphere and Environmental Physics"Neue Sektion "Physik der Erde, Atmosphäre und Umwelt"

Nouvelle section "Physique du Globe et de l’Environnement"

11


Allgemeine Tagungsinformationen - Informations générales sur la réunion

Konferenzwebseite und AnmeldungAlle Teilnehmeranmeldungen werden über die Konfe-renzwebseite vorgenommen. www.sps.ch -> Veranstaltungen

Anmeldeschluß: 1. Juni 2012

TagungsortETH Zürich, Hönggerberg, Gebäude HPH / HCI

TagungssekretariatDas Tagungssekretariat befindet sich im Foyer des HPH direkt neben dem Haupteingang.Öffnungszeiten: Mittwoch 20. Juni 16:00 - 19:00 Donnerstag 21. Juni 08:00 - 18:00 Freitag 22. Juni 08:00 - 15:00

Alle Tagungsteilnehmer melden sich bitte vor dem Be-such der ersten Veranstaltung beim Sekretariat an, wo Sie ein Namensschild und allfällige weitere Unterlagen erhalten sowie die Tagungsgebühr bezahlen.Wichtig: Ohne Namensschild ist kein Zutritt zu einer Veranstaltung möglich.

Wir empfehlen Ihnen, wenn möglich den Mittwoch Nachmittag für die Anmeldung zu nutzen. So können Sie am Donnerstag direkt ohne Wartezeiten die Vorträge besuchen.

Achtung: Das Tagungssekretariat gibt kein technisches oder Büromaterial ab. Jeder Teilnehmer ist für seine Ausrüstung (Mobilrechner, Laserpointer, Adapter, Sche-re, Reissnägel, Folien usw.) selber verantwortlich !

HörsäleIn allen Hörsälen stehen Beamer und Hellraumprojek-toren zur Verfügung. Bitte bringen Sie Ihre eigenen Mo-bilrechner und evtl. Adapter und USB Stick/CD mit.

PostersessionDie Postersession findet am Donnerstag Abend und am Freitag während der Mittagspause im Foyer HPH statt. Bitte bringen Sie Befestigungsmaterial (Reiss-nägel, Klebestreifen) selbst mit. Die Posterwände sind entsprechend diesem Programm numeriert, sodaß jeder Teilnehmer "seine" Wand leicht finden sollte. Alle Poster sollen an beiden Tagen präsentiert werden.Maximale Postergröße: A0 Hochformat

ZahlungWir bitten Sie, die Tagungsgebühren im Voraus zu be-zahlen. Sie verkürzen damit die Wartezeiten am Ta-gungssekretariat, erleichtern uns die Arbeit und sparen darüber hinaus noch Geld !Sie können auf das folgende Konto einzahlen / überwei-sen:

Postkonto der Schweizerischen Physikalischen Gesellschaft, CH-4056 Basel,Kontonummer 80-8738-5

Site web de la conférence et inscriptionL' inscription des participants se fait sur le site web de la conférence. www.sps.ch -> Evènements

Délai d'inscription: 1er juin 2012

Lieu de la conférenceETH Zürich, Hönggerberg, bâtiment HPH / HCI

Secrétariat de la conférenceLe secrétariat de la réunion se trouve dans le foyer du bâtiment HPH juste à l'entrée.Heures d'ouverture : Mercredi 20 juin 16:00 - 19:00 Jeudi 21 juin 08:00 - 18:00 Vendredi 22 juin 08:00 - 15:00

Tous les participants doivent se présenter en premier lieu au secrétariat de la conférence afin de recevoir leur badge et les divers documents ainsi que pour le paie-ment des frais d'inscription.Attention: Sans badge, l'accès aux sessions de la ma-nifestation sera refusé.

Nous vous recommandons de vous inscrire déjà mer-credi après-midi afin d'éviter des temps d'attente inu-tiles jeudi matin.

Attention: Le secrétariat de la conférence ne rend au-cun matériel technique ni matériel de bureau. Chaque participant est responsable de son équipement (ordina-teur, pointeur laser, adaptateurs, ciseaux, punaises, ...) !

AuditoiresLes auditoires disposent tous d’un projecteur multi-média (beamer) et d'un projecteur pour transparents. Veuillez apporter votre ordinateur portable ainsi que d'éventuels accessoires tels que clé USB ou CD.

Séance postersLes posters seront présentés dans le foyer HPH le jeudi soir et pendant la pause de midi de vendredi. Veuillez amener vous-même le matériel nécessaire pour fixer les posters (punaises, ruban adhésif). Les panneaux de posters seront numérotés suivant le numéro de l'abs-tract indiqué dans le programme. Tous les posters pour-ront rester installés pendant les deux jours.Dimension maximale: A0, format portrait

PaiementNous vous prions de régler d'avance vos frais d'inscrip-tion par virement postal ou bancaire. De cette manière vous éviterez des files d'attente et vous nous facilitez notre travail. En plus vous pourrez faire des économies !Vous pouvez effectuer votre virement sur le compte sui-vant:

Compte postale de la Société Suisse de Phy-sique, CH-4056 Basel,Numéro 80-8738-5

12


Für Zahlungen aus dem Ausland verwenden Sie bitte folgende Angaben:IBAN: CH59 0900 0000 8000 8738 5SWIFT/BIC: POFI CH BE XXX

Bitte achten Sie darauf, daß Ihr Name und der Zahlungs-zweck angegeben werden. (Es reicht nicht, wenn als Ab-sender beispielsweise nur "Uni Basel" erscheint, da wir eine solch allgemeine Angabe nicht einer Einzelperson zuordnen können.)

Am Tagungssekretariat kann nur bar bezahlt werden (in CHF). Kreditkarten können leider nicht akzeptiert wer-den.

ACHTUNG: Tagungsgebühren können nicht zurücker-stattet werden.

Kaffeepausen, MittagessenDie Kaffeepausen, der zur Postersitzung gehörende Apéro am Donnerstag Abend sowie das Lunchbuffet am Freitag finden in Foyer HPH bei der Poster- und Händ-lerausstellung statt. Diese Leistungen sind in der Konfe-renzgebühr enthalten.Für das Mittagessen am Donnerstag stehen die Mensen auf dem Campus Hönggerberg zur Verfügung (www.gastro.ethz.ch).

GrillpartyDie Grillparty findet am Donnerstag im Anschluß an die Postersession statt. Der Preis beträgt CHF 90.- pro Per-son (beinhaltet Essen und Getränke) Bitte registrieren Sie sich unbedingt im Voraus, damit wir disponieren können. Eine Anmeldung vor Ort ist nicht möglich !

Spezialangebot für "Noch-Nicht" SPG-MitgliederPlanen Sie, an unserer Tagung teilzunehmen sowie Mit-glied der SPG zu werden ? Sie können nun beides für einen äusserst günstigen Preis von nur CHF 150.- (CHF 170.- nach dem 1. Juni). Dieser Betrag deckt die Kon-ferenzgebühr sowie die Mitgliedschaft für 2012. Verpas-sen Sie dieses Angebot nicht ! Wählen Sie einfach bei der Online Registrierung die Kategorie "Special Offer", laden Sie das Anmeldeformular ( http://www.sps.ch/uploads/media/anmeldeformular_d-f-e.pdf ) für neue Mitglieder herunter, drucken es aus und schicken oder faxen es ausgefüllt an das SPG-Sekretariat.

Pour des paiements en provenance de l'étranger veuillez utiliser les données suivantes:IBAN: CH59 0900 0000 8000 8738 5SWIFT/BIC: POFI CH BE XXX

N'oubliez pas d'indiquer votre nom et le motif de votre paiement (la mention "Uni Bâle", par exemple, est trop générale et ne suffit pas à identifier l'auteur du virement.)

Les paiements lors de la conférence ne pourront être effectués qu'en espèces (CHF). Les cartes de crédit ne pourront malheureusement pas être acceptées.

ATTENTION: Les frais d'inscription ne pourront pas être remboursés.

Pauses café, repas de midiLes pauses café, l'apéro accompagnant la séance posters du jeudi soir et le buffet de midi du vendredi se dérouleront dans le foyer HPH près des posters et exposants. Ces prestations sont inclues dans les frais d'inscription.Pour le repas de midi du jeudi les restaurants du cam-pus Hönggerberg sont à votre disposition (www.gastro.ethz.ch).

GrillpartyLa grillparty se tiendra le jeudi soir après la séance pos-ters. Le prix est de CHF 90.- par personne (repas et boissons inclus). Veuillez s.v.p. absolument vous enre-gistrer d'avance pour des raisons d'organisation. Il n'est plus possible de s'inscrire sur place.

Offre spéciale pour les non-membres de la SSPVoulez-vous participer à la conférence et devenir aus-si membre de la SSP ? Profitez de notre offre avanta-geuse ! Pour la somme de CHF 150.- (CHF 170.- après le 1er juin) nous vous offrons l’inscription ainsi que la co-tisation de membre de la SSP jusqu’à fin 2012. Ne ratez pas cette occasion! Cochez simplement la case « Spe-cial Offer » lors de votre inscription en ligne, téléchargez le formulaire d’admission à la SSP de http://www.sps.ch/uploads/media/anmeldeformular_d-f-e.pdf , impri-mez-le, et renvoyez-le dûment rempli par courrier ou par fax au secrétariat de la SSP.

Preise gültig bei Zahlung bis 1. Juni - Prix valable pour des paiements avant le 1er juin

Kategorie - Catégorie CHF

SPG-Mitglieder, Doktoranden - Membres de la SSP, Doctorants 100.-

Studenten VOR Master/Diplom Abschluß - Etudiants AVANT le degré master/diplôme 30.-

Plenar-/Eingeladene Sprecher, Preisträger - Conférenciers pléniers / invités, lauréats 0.-

Andere Teilnehmer - Autres participants 140.-

Spezialangebot für "Noch-nicht-SPG-Mitglieder" (s.u.) - Offre spéciale pour "Non-membres de la SSP" (voir ci-dessous.)

150.-

Grillparty 90.-

Zuschlag für Zahlungen nach dem 1. Juni sowie Barzahler an der Tagung -Supplément pour paiements effectués après le 1er juin et pour paiements en espèces à la conférence

20.-

13


(Cette offre n’est pas valable pour les étudiants et les doctorants. Ceux-ci profitent en effet d’une affiliation gratuite à la SSP pendant la première année, et ne paient que les frais d’inscription indiqués dans le tableau ci-dessus.)

HôtelsLes réservations d'hôtel peuvent être effectuées sur la page internet de Zürich Tourisme (www.zuerich.com).

Arrivéehttp://www.ethz.ch/about/location/hoengg/index_EN vous donne les informations détaillées sur l'arrivée avec les différents moyens de transport. Au campus veuillez suivre les panneaux de la conférence.

(Dieses Angebot gilt nicht für Studenten oder Doktoran-den. Diese profitieren sowieso von der Gratis-Mitglied-schaft im ersten Mitgliedsjahr, und zahlen nur die in der Tabelle angegebene Konferenzgebühr.)

HotelsHotelreservierungen können direkt über Zürich Touris-mus (www.zuerich.com) vorgenommen werden.

AnreiseUnter http://www.ethz.ch/about/location/hoengg finden Sie ausführliche Hinweise zur Anreise mit verschiedenen Verkehrsmitteln. Auf dem Campus folgen Sie einfach den Hinweisschildern.

14


ETH Zürich – Standort Hönggerberg (Campus Science City)

Glaubten

strasse

SchauenbergstrasseEm

il-Klöti-Strasse

Wolfgan

g-Pa

uli-S

trasse

37/80

P

P

Schafmattstrasse

37/69/80Einsteinstrasse

4

3

2

1

A B C D

Bushaltestelle

ETH-Pendelbus «Science City Link»

Mensa

Cafeteria

Science City Welcome Desk (Telefon +041 44 633 64 44)

Herausgeberin: ETH Zürich, Hochschulkommunikation, Mai 2011

Kartenmaterial: Institut für Kartographie der ETH Zürich, bearbeitet von Immobilien,

Stab Portfoliomanagement und Hochschulkommunikation

Alle Gebäude und Parkgaragen sind rollstuhlgängig. Weitere Informationen am Science City Welcome Desk.

Parking entryconference

15


Vorläufige Programmübersicht - Résumé préliminaire du programmeDas vollständige Programm wird allen Teilnehmern am Ta-gungssekretariat abgegeben sowie auf der SPG-Webseite publiziert.Hinweise:

- Je Beitrag wird nur der präsentierende Autor aufgeführt.- Die Postersitzung ist am Donnerstag von 18:30 - ca.

20:00 (mit Apéro) sowie am Freitag von 12:00 - 13:30 (mit Lunchbuffet)

- (p) = Plenarsprecher, (i) = eingeladener Sprecher

Le programme final complet sera distribué aux participants au stand du secrétariat de la conférence et sera publié sur le site de la SSP.Indication:

- seul le nom de l’auteur présentant la contribution a été indiqué.

- la session poster a lieu le jeudo de 18.30 à env. 20.00 (avec apéro) ainsi que le vendredi de 12:00 à 13:30 (avec buffet de midi)

- (p) = orateur de la session plénière, (i) = orateur invité

Plenary Session

Thursday, 21.06.2012, HPH G 1

Time ID Plenary SeSSion iChair: Christophe Rossel, IBM Rüschlikon

08:55 Welcome note of the SPS President

09:00 1 From the QHE to Topological Insulators and on to Cosmic Magnetic Fields - a Unified PerspectiveJürg Fröhlich, ETH Zürich (p)

09:40 2 Quantum physics in one dimensionThierry Giamarchi, Uni Genève (p)

10:20 Coffee Break

Chair: Gervais Chapuis, EPFL

10:50 3 From Laue's discovery and the Braggs' key to the world of atoms to service crystallographyDieter Schwarzenbach, EPFL (p)

11:30 Award Ceremony

11:50 SPS General Assembly

12:30 Lunch

13:30 Topical Sessions

18:30 Postersession and Apéro

20:15 Grillparty


Time ID Public lecture

Chair: Martin Pohl, Uni Genève

19:00 11 Space-borne Cosmic Ray DetectorsSamuel C. C. Ting, CERN & MIT (p)

20:15 END

Friday, 22.06.2012, HPH G 1

Time ID Plenary SeSSion iiChair: NN

09:00 4 Nanomechanical Resonators - coherent control of nanomechanical motionJörg Peter Kotthaus, LMU München (p)

09:40 5 Charge, Spin And Structural Dynamics of molecular systems: ultrafast optical and X-ray studiesMajed Chergui, EPFL (p)

10:20 Coffee Break


12:00 Postersession (continued), Lunchbuffet


Friday, 22.06.2012, HPH G 2

Time ID Public tutorial of nccr MuSt and eth faStChair: Ursula Keller, ETH Zürich

12:15 12 Ultrafast BiologyGebhard F. X. Schertler, ETH Zürich & PSI Villigen (p)

13:00 END

Special: Careers for Physicists

This session is organised in conjunctionwith the Physikalische Gesellschaft Zürich (PGZ).


Time ID careerS for PhySiciStS

Chair: Kai Hencken, ABB Baden

13:30 31 Sensirion: High-Tech Sensors from the ZürichseeMarc von Waldkirch (i)

14:00 32 Physicists in research administrationFlorian Weissbach (i)

14:30 33 Theoretical Physics in Industrial Corporate Re-searchThomas Christen (i)

15:00 34 Mesa Imaging: Seeing the world in three dimen-sionsThierry Oggier (i)

15:30 END, Coffee Break


Special: Teacher's Afternoon:"Nanophysik am Gymnasium"

Friday, 22.06.2012, HCI D 2

Time ID "nanoPhySik aM gyMnaSiuM"Chair: Tibor Gyalog, Uni Basel

14:30 41 Nano 4 schools - Erfahrungsbericht über 9 Jahre Nano für SchulenMartin Vonlanthen (i)

14:50 42 Der Nanotruck in Deutschland – Eine ErfolgsstoryAndreas Jungbluth (i)

15:10 43 Swiss nano Cube - Plattform für Wissen & Bildung zu NanotechnologienRobert Rekece (i)

15:30 Coffee Break

16


Time ID Chair: Tibor Gyalog, Uni Basel

16:00 44 Graetzelzellen für die SchuleThilo Glatzel (i)

16:20 45 Nanomedizin – Eine Debatte über TechnologiefolgenMeret Hornstein (i)

16:40 46 Nano-Experimentier-Systeme für die SchuleAndreas Vaterlaus (i)

17:00 47 War Benjamin Franklin der erste Nanophysiker?Danilo Pescia

17:20 END

Special:A. 100 Years of Diffraction: Historical highlights and a

look into the next 100 years

This session is organised by the Swiss Society for Crystallography (SGK).Part I is jointly organised with the SPS History of Physics section.

Thursday, 21.06.2012, HCI J 6

Time ID i. 100 yearS of diffraction

Chair: Jan Lacki, Uni GenèveAnthony Linden, Uni Zürich

11:50 SGK General Assembly

12:30 Lunch

13:30 51 The two BraggsA. Michael Glazer (i)

14:00 52 Max von Laue: the physicist and the upright manJost Lemmerich (i)

14:30 53 The origins and development of macromolecular crystallographyLarry Falvello (i)

15:00 54 Johannes Martin Bijvoet (1892-1980) and absolute structureTon Spek (i)

15:30 Coffee Break

ii. the next 100 yearS

Chair: Michael Wörle, ETH Zürich

16:00 61 Novel structural studies with an X-ray Free Electron LaserBruce Patterson (i)

16:25 62 Investigating disorder as a matter of routine - the next stepsThomas Weber (i)

16:50 63 The Materials Science Beamline upgradePhilip Willmott (i)

17:15 64 High Resolution X-Ray Diffraction applications for microsystemsAntonia Neels

17:30 65 Powder Charge Flipping – input parameter optimi-zation and solution evaluationDubravka Šišak

17:45 66 Intercluster compounds for nanosized materialsFabienne Gschwind

18:00 67 News from the spallation neutron source SINQ: Dif-fractionJürg Schefer

18:15 68 Density functional calculations of polysynthetic Brazil twinning in alpha-quartzHans Grimmer

18:30 Poster prize and closing remarks

18:35 END, Postersession and Apéro

20:15 Grillparty

ID 100 yearS of diffraction PoSter

71 A moment in time: 100 years of X-Ray diffraction versus 100 days of PHOTON 100 CMOS detectorEric Hovestreydt

72 Ab-initio crystal structure prediction. Metal borohydridesRiccarda Caputo

73 Pressure modulated proton-phonon coupling and its relevance to ceramic fuel cell proton conductorsQianli Chen

74 Mixed-metal precursors for mixed-metal oxidesClaire-Lise Chanez

75 New penta-coordinate iron(III) aryloxide as initiators for ring-opening polymerizationYvens Chérémond

76 Light-induced low-spin structure of the bistable [Fe(bbtr)3](BF4)2 compoundLaure Guenee

77 Magnetic ground state and 2D behavior in the pseudo-Kagomè layered system Cu3Bi(SeO3)2O2BrOksana Zaharko

78 XRD investigations on PZT layers for actuator systemsOlha Sereda

79 Novel trimetallic borohydridesPascal Schouwink

80 TIPSI hybrid spectrometer at the European Spallation Neutron Source ESS: Probing multiple length scales in one instrumentNadir Aliouane

81 Neutron diffraction and Oxygen Isotope Back Exchange studies in La2-xSrxCuO4±

(x = 0, 0.05, 0.15) crystals as a function of temperatureRavi Sura

82 Our fascination with crystals and crystallography – a 7500 year timelineRangana Warshamanage

B. History of Physics

Thursday, 21.06.2012, HCI D 2

Time ID hiStory of PhySicS

Chair: NN

14:30 91 The method of Victor F. Hess, or how the residual leaking away of electric charge, a tenacious ‘shelf warmer‘, opened up new fascinating fields of physi-cal knowledgePeter Schuster (i)

15:00 92 From thunderstorms to cosmic rays: Albert Gock-el’s investigations in atmospheric physicsJan Lacki

15:30 Coffee Break

Chair: NN

16:00 93 The origins and fate of technical physics in Lausanne: the creation of the Ecole Spéciale.Régis Catinaud

16:30 94 Who discovered the Proca equation ? Lanczos, Pro-ca, de Broglie and the development of relativistic quantum theory in the 30’Adrien Vila-Valls

17


17:00 95 Density-functional-theory strategy to solve ap-proximately a quantum many-body problem: main ideas over the last 50 years and their reflection in terminologyTomasz Wesolowski

17:30 96 Political Decisions with deep Scientific Conse-quencesAraceli Sanchez Varela

18:00 97 A key to success for an instrument maker: Collabo-ration with a scientist. The case of Haag-Streit (es-tablished 1858) and Heinrich Wild (1833-1902).Jean-François Loude

18:30 END, Postersession and Apéro

20:15 Grillparty

1 Magnetism at Interfaces


Time ID MoleculeS and cluSter

Chair: Armin Kleibert, PSI Villigen

13:30 101 Magnetic exchange coupling at the metal-organic molecule/substrate interface: Insights from first-principles calculationsPeter Oppeneer (i)

14:00 102 Investigating the interplay of geometry and mag-netism in spin shuttle molecules on surfacesThomas Greber (i)

14:30 103 Novel magnetochemical effects induced by axial ligands in on-surface planar molecular spin sys-temsChristian Wäckerlin

14:45 104 Magnetism of Fe nanocluster superlattices on Al2O3/NiAl (111)Luca Gragnaniello

15:00 105 Towards spintronics with Erbium single-ion molec-ular magnetsJan Dreiser

15:15 106 High anisotropies for bimetallic Co-core Fe-shell islands on Au(11,12,12)Sergio Vlaic

15:30 Coffee Break

Magnetic and ultrafaSt interfaceS

Chair: Cinthia Piamonteze, PSI Villigen

16:00 111 Superconductivity, magneto-transport and elec-tronic structure of the interfacial LaAlO3/SrTiO3 electron gasJean-Marc Triscone (i)

16:30 112 Interfacial magnetic couplings at LaSrMnO3 inter-facesCarlos Vaz

16:45 113 The Nature of Magnetic Ordering in Magnetically Doped Topological Insulator Bi2-xFexSe3 - From Bulk to SurfaceZaher Salman

17:00 114 Strain-driven magnetization in epitaxial multiferroic composite heterostructures mapped with x-rays and neutronsRajesh Chopedekar

17:15 115 Altering STO/vacuum interface electronic states depositing polar LAO epitaxial film: Angle Resolved Photoemission Spectroscopy studyMilan Radovic

17:30 116 Search for spontaneous magnetism below the sur-face of (110)-oriented YBCO superconducting films using LE-μSRHassan Saadaoui

17:45 117 Ultrafast Enhancement of Ferromagnetism via Pho-toexcited Carriers in EuOMasakazu Matsubara

18:00 118 Coherent control of femtosecond magnetization dynamics by a strong THz pulseChristoph Hauri

18:15 119 Ultrafast magnetism seen by time and spin resolved photoemission at FLASHAndreas Fognini


20:15 Grillparty

Friday, 22.06.2012, HCI J 7

Time ID nanowireS and nanoParticleS

Chair: Carlos Vaz, PSI Villigen

11:00 121 Static and dynamic properties of Single-Chain Mag-nets with broad domain wallsAlessandro Vindigni

11:15 122 Thermal fluctuations and domain walls in ultra-thin magnetic nanowiresThomas Michaelis

11:30 123 Searching for magnetic structural excitations at the nano-scalePeter Derlet

11:45 124 Domain Walls in Structured Ferromagnetic Na-nowiresVahe Tshitoyan

12:00 125 Temperature-dependent magnetization of individu-al iron nanoparticles studied with X-ray Photoemis-sion electron microscopyAna Balan

12:15 END, Postersession (continued), Lunchbuffet

ID MagnetiSM at interfaceS PoSter

131 Use of a Landau-Heisenberg Hamiltonian in modelling the FeRh SystemPeter Derlet

132 Magnetization dynamics of GdFeCo nanostructures re-vealed with PEEMSouliman el Moussaoui

133 Coupled vortex pairs in magnetic multilayer elementsChristoph Quitmann

134 Ground state ordering of artificial spin iceAlan Farhan

135 Domain pattern breakup in mesoscopic structures studied with x-ray microscopyStephanie Stevenson

136 Ultrafast laser induced spin reorientation in the Co/SmFeO3 heterostructureArmin Kleibert

137 Studying the interfacial magnetism of LaNiO3/LaMnO3 su-perlattices with x-ray magnetic circular dichroismCinthia Piamonteze

138 Size-dependent magnetic properties of individual iron na-noparticles studied at room temperatureAna Balan

139 Luminescence-based scanning x-ray transmission micros-copyCarlos Vaz

18


140 Enhancement of spin fluctuations of TbPc2 single molecule magnets in thin filmsAndrea Hofmann

141 Electric field control of magnetism in epitaxial Pd thin filmsJakoba Heidler

142 Radiation-induced elemental magnetic changes in Fe-Cr al-loys using XMCD techniqueAndi Idhil

143 Impurity Band Responsible for Ferromagnetism in Magnet-ic Semiconductor (Ga,Mn)AsMasaki Kobayashi

144 Digging up Bulk Band Dispersion behind Passivation LayerMasaki Kobayashi

145 Three-Dimensional Fermi Surface of Iron-Pnictide Super-conductor BKFAMasaki Kobayashi

2 Applied Physics+

Atomic Physics and Quantum Optics

note:the atoMic PhySicS and QuantuM oPticS SeSSion

containS only PoSter PreSentationS.

Friday, 22.06.2012, HCI J 6

Time ID aPPlied PhySicS iChair: Ivo Furno, CRPP-EPFL

11:00 201 Vector Spherical Harmonics for active magnetic field compensationGrzegorz Wyszynski

11:15 202 Handling wide dynamic PMT signals with high pre-cision in ground-based gamma-ray detectorsArno Gadola

11:30 203 A new internal field mapping device for the nEDM experimentDieter Ries

11:45 204 High brilliance electron beam extraction from me-tallic microstructured photocathodeArdana Fernando


aPPlied PhySicS iiChair: NN

13:30 211 Cocaine Detection in Saliva with Attenuated Total Reflection (ATR) SpectroscopyKerstin Hans

13:45 212 Sensitive detection of cocaine in a liquid solvent with a quantum cascade laserMichele Gianella

14:00 213 Mid-infrared fiber-coupled photoacoustic sensor for the detection of glucose in biological samplesJonas Kottmann

14:15 214 Tracking of Murine Cardiac Stem Cells by Harmonic NanoparticlesThibaud Magouroux

14:30 215 Analysis of Human Tone-Burst-Evoked Otoacoustic EmissionsReinhart Frosch

14:45 216 High power SESAM modelocked thin disk lasers: access to sub-100 fs pulses and first CEO beat fre-quency detectionCinia Schriber

15:00 217 Enhancing the Performance of Solid State Organic Solar Cells by Self-assembled Monolayer TechniqueAli Kemal Havare

15:15 218 Wave Propagation in Elastic and Thermoelastic Ma-terialsMario Leindl

15:30 Coffee Break

aPPlied PhySicS iiiChair: NN

16:00 221 Highly efficient Cu(In,Ga)Se2 solar cells grown on flexible polymer filmsAdrian Chirilă (i)

16:30 222 Dynamic nuclear polarization at moderate mag-netic fields and temperature using photo-excited triplet states of aromatic moleculesTim Rolf Eichhorn

16:45 223 Dynamical study of electron pump based on self-assembled quantum dotsGiancarlo Cerulo

17:00 224 DAST/SiO2 multilayer structure for efficient genera-tion of 6 THz single-cycle pulses via cascaded opti-cal rectificationAndrey Stepanov

17:15 225 Laser induced magnetization reversal in GdFeCo nanostructuresMichele Buzzi

17:30 226 Electrochemical deposition of photoconductive sili-con based films using organic solventsAgata Krywko-Cendrowska

17:45 END

ID aPPlied PhySicS PoSter

241 Optical position feedback and closed loop control for elec-trostatically driven MOEMS mirrorsAndreas Tortschanoff

242 Structural and piezoelectric investigation of BaTiO3 thin films on SiMarilyne Sousa

243 Strain effects on the properties of III-V MOSFETsPirmin Weigele

244 Physical properties of ZnSe/SnO2/glass films: Annealing (Ar atmosphere) temperature effectsHulya Metin

245 Structural and Electrical properties of Inkjet Printed CdS Thin FilmsHulya Metin

246 Characterization of Inkjet Printed CdTe Thin FilmHulya Metin

247 Electrical Properties and Crystallographic Properties of Ter-nary Ho2O3 and Eu2O3 Doped Bi2O3 PolymorphsHulya Metin

248 Electrical Properties And Crystallographic Characterisation of (Bi2O3)1-x-y(Ho2O3)x and (Tm2O3)y SystemHulya Metin

249 Surface morphology and Thermoluminescence of CBD grown ZnSe FilmsSelma Erat

250 Scattered light fluorescence microscopy in three dimensionsGiulia Ghielmetti

251 Sensitivity of RADFETs with various gate oxide thicknessesGoran Ristic

19


ID atoMic PhySicS and QuantuM oPticS PoSter

281 Spectral properties of mid-infrared quantum cascade lasersLionel Tombez

282 Simple approximate relation between laser frequency noise and linewidth: experimental validationNikola Bucalovic

283 External cavity tuning of broadband QCLs at 3.3 μm and 8 μmSabine Riedi

284 Ground state Hanle effect based on atomic alignment:theory and experiment.Evelina Breschi

285 Study of phase gradients in the Swiss continuous atomic fountain frequency standardLaurent Devenoges

286 Femtosecond gigahertz diode-pumped solid-state laser for frequency comb generationAlexander Klenner

287 Ultrafast optically pumped VECSELs and MIXSELsMario Mangold

288 Mid-IR Broadband Quantum Cascade Laser Frequency-CombAndreas Hugi

289 Single-cycle high-power THz pulses above 1 MV/cmCarlo Vicario

3 Nuclear, Particle- and Astrophysics


Time ID taSk i: neutrinoS, aStroParticle PhySicS

Chair: Martin Pohl, Uni Genève

13:30 301 Sterile neutrinos: dark matter, baryogenesis, mag-netic fields and more...Oleg Ruchayskiy

13:45 302 Dark Matter search with the XENON100 experimentMarc Schumann

14:00 303 The Argon Dark Matter ExperimentLukas Epprecht

14:15 304 Measurements of the low-energy response of liquid xenonAaron Manalaysay

14:30 305 Towards a large underground liquid argon observa-tory for neutrino physics and proton decayAlessandro Curioni

14:45 306 On Flight Performances of the AMS-02 Detector and Preliminary Results on the Proton and Helium Energy SpectrumPierre Saoute

15:00 307 POLAR: a Gamma-Ray Burst Polarimeter in SpaceSilvio Orsi

15:15 308 The FACT telescope - overview and statusPatrick Vogler

15:30 Coffee Break

taSk ii: PSi PhySicS i and lhc PhySicS iChair: Klaus Kirch, ETH Zürich

16:00 311 New and final results of the MuCap experimentClaude Petitjean

16:30 312 Measurement of the Positive Pion Lifetime, tp

+, with the FAST Detector at the Paul Scherrer InstituteGaetano Barone

16:45 313 Muonium emission into vacuum from mesoporous thin films at cryogenic temperaturesKim Siang Khaw

17:00 314 Qualification procedures of the CMS digital readout chip for the Pixel Upgrade Phase IPhilipp Eller

17:15 315 Search for the Higgs boson in the diphoton decay channel at CMSMarco Peruzzi

17:30 316 Measurements of the electron and muon inclusive cross-sections in proton-proton collisions at s = 7 TeV with the ATLAS detectorMaria Clemencia Mora Herrera

17:45 317 HammerCloud: distributed computing monitoring for ATLAS and LHC experimentsGianfranco Sciacca

18:00 318 Search for supersymmetry in hadronic final states with MT2 with the CMS detectorHannsjörg Weber

18:15 319 Angular correlation between B-hadrons produced in association with a Z boson at the CMS experi-mentCarlotta Favaro


20:15 Grillparty

Friday, 22.06.2012, HCI J 3

Time ID taSk iii: lhc PhySicS iiChair: T. Montaruli

11:00 321 Search for the Standard Model Higgs Boson decay-ing to Bottom QuarksPierluigi Bortignon

11:15 322 New Optical receiver modules for the insertable B-Layer at the ATLAS project.Basil Schneider

11:30 323 Improvements in the search for a Higgs boson de-caying into bottom quarksPhilipp Eller

11:45 324 B-baryon studies at the CMS ExperimentMirena Ivova


taSk iV: lhc PhySicS iiiChair: Antonio Ereditato, Uni Bern

13:30 331 Search for Supersymmetry in Events with a Z Bo-son, Jets and Missing EnergyMarco - Andrea Buchmann

13:45 332 Searches for the 4th Generation top-like QuarkSnezana Nektarijevi

14:00 333 Top analysis from the bottom: Jet performance is-sues in top quark measurements by the ATLAS ex-periment at the LHC.Caterina Doglioni

14:15 334 Jet angular resolutionFrancesco Guescini

14:30 335 Measurement of the Zero-Crossing Point of the for-ward - backward Asymmetry of B0 " K*0 μ+ μ-

Marco Tresch

14:45 336 Measurement of lifetime difference Ds in the decay Bs " (J/) " (μ+ μ-) K+ K-

Barbara Millan Mejias

15:00 337 A data driven QCD-multijet background estimate for top physics with the ATLAS detectorKilian Rosbach

15:15 338 New searches for magnetic monopolesPhilippe Mermod

20


15:30 Coffee Break

taSk V: lhc PhySicS iV and PSi PhySicS iiChair: Giuseppe Iacobucci, Uni Genève

16:00 341 Search for a neutron electric dipole moment at PSIJochen Krempel

16:15 342 Systematic effects in the nEDM experiment at PSIJohannes Zenner

16:30 343 Improvements of the Hg cohabiting magnetometer for the nEDM experiment at PSIMartin Fertl

16:45 344 Results of the active compensation of the magnetic field surrounding the nEDM apparatus at PSIBeatrice Franke

17:00 345 Simultaneous Heavy Flavor and Top (SHyFT) Cross Section MeasurementLukas Bäni

17:15 346 Radiation hard studies of diamond strip trackersFelix Bachmair

17:30 347 Search for the Rare Decays B0s " μ+ μ- and

B0 " μ+ μ- at LHCbChristian Elsasser

17:45 348 Search for (Higgs-like) bosons decaying into long-lived exotic particlesJulien Rouvinet

18:00 349 Tagged time-dependent angular analysis ofB0

s " J/ decays at LHCbFrédéric Dupertuis

18:15 350 b-baryon results at LHCbRaphael Märki

18:30 END

ID nuclear, Particle- and aStroPhySicS PoSter

361 LOFT - the Large Observatory for X-ray TimingEnrico Bozzo

362 The search for neutrinoless double beta decay with the GERDA experimentGiovanni Benato

363 Search for Physics Beyond the Standard Model in Events with equally charged LeptonsMarc Dünser

364 Performance validation of the CMS digital readout chip with x-rays for the Phase I Pixel UpgradeMarco Rossini

365 Longitudinal spatial compression of a slow muon beamYu Bao

366 Optical cesium magnetometers for the PSI neutron electric dipole moment experimentMalgorzata Kasprzak

367 Search for Supersymmetry in multilepton final statesTobias Kruker

368 Measurement of Pion and Kaon production cross sections with NA61/SHINE for T2KSilvestro di Luise

369 Parametric r-process studies in supernova shocksMarius Eichler

370 Die Grundzüge der WeltpotentialtheoriePeter Wolff

371 Das Lehrplakat zur Weltpotentialtheorie (WPT)Peter Wolff

4 Theoretical Physics


Time ID theoretical PhySicS iChair: G. M. Graf, ETH Zürich

13:30 401 Electron waiting time distributions in electrical con-ductorsMarkus Büttiker (i)

14:00 402 Gravitational wave detection from spacePhilippe Jetzer (i)

14:30

15:30 Coffee Break

theoretical PhySicS iiChair: G. M. Graf, ETH Zürich

16:00 403 A new algorithm to compute one-loop scattering amplitudesFabio Cascioli

16:15 404 Application of the Symbol Formalism to the Com-putation of Scattering Amplitudes in Quantum Field TheoryErich Weihs

16:30 405 Polycrystalline Shape Memory Alloys: Constitutive Modelling by the BSM (Block-Spin-Method)Eduard Oberaigner

16:45 406 One-dimensional fermionic systems beyond Lut-tinger liquid theoryThomas Schmidt

17:00 407 Stability of topological quantum computing schemes to bit-flip and measurement errorsRuben S. Andrist

17:15 408 Euclid and the quest for the Dark EnergyMartin Kunz

17:30


20:15 Grillparty

Friday, 22.06.2012, HCI J 4

Time ID theoretical PhySicS iiiChair: G. M. Graf, ETH Zürich

11:00 411 The quantum marginal problemMatthias Christandl (i)

11:30 412 What can we learn from the cosmological matter distribution?Ruth Durrer (i)


theoretical PhySicS iVChair: G. M. Graf, ETH Zürich

13:30 413 Cavity optomechanics in the single-photon strong-coupling regimeAndreas Nunnenkamp (i)

14:00 414 Controlling electronic interactions by lightPhilipp Werner (i)

14:30 415 Hybridization of wave functions in one-dimensional Anderson localizationDmitri Ivanov (i)

15:00

15:30 Coffee Break

theoretical PhySicS VChair: G. M. Graf, ETH Zürich

16:00 416 Dynamics of the rotated Dicke modelMichael Tomka

21


16:15 417 Bethe Ansatz and Ordinary Differential Equation Correspondence for Degenerate Gaudin ModelsOmar El Araby

16:30 418 Eigenvector statistics in a perturbed weakly-confined random matrix ensembleMatous Ringel

16:45 419 Symbolic Computation in Lagrangian MechanicsMario Leindl

17:00 END

5 NCCR MaNEP


Time ID ManeP iChair: Dirk van der Marel, Uni Genève

13:30 501 Competition between charge order and supercon-ductivity in YBa2Cu3Oy

Marc-Henri Julien (i)

14:00 502 Scanning Tunneling Spectroscopy on YBa2Cu3O7−

revisitedJens Bruér

14:15 503 Magnetic-field tuned anisotropy in superconduct-ing RbxFe2−ySe2Saskia Bosma

14:30 504 Universal scaling collapse of the dynamic relaxa-tion rate in underdoped high Tc cupratesSeyed Iman Mirzaei

14:45 505 Structural and Magnetic Properties of the Parent Compound T’-La2CuO4 of Electron-Doped CupratesGwendolyne Pascua

15:00 506 Field effect experiments on cuprates and related materialsGuy Dubuis

15:15 507 Prospects for improving the superconducting prop-erties of MgB2 and Nb3Sn wiresCarmine Senatore

15:30 Coffee Break

ManeP iiChair: Christoph Renner, Uni Genève

16:00 511 From surface to interface physics: High-energy photoemission spectroscopy of oxide heterostruc-turesRalph Claessen (i)

16:30 512 Theory of High-Temperature Multiferroicity in CuONaemi Leo

16:45 513 Radio-frequency spectroscopy of a weakly attrac-tive Fermi gasChristophe Berthod

17:00 514 Multiscaling analysis of ferroelectric domain wall roughnessJill Guyonnet

17:15 515 Fermi Surface Dependence of the Charge Transport and Thermoelectric Effect in Two-Dimensonal Met-alsJonathan M. Buhmann

17:30 516 Magnetotransport properties of LaAlO3/SrTiO3 in-terfacesAlexandre Fête

17:45 517 Exchange Bias in LaNiO3-based heterostructuresPavlo Zubko

18:00 518 Correlated transition metal oxides for thermo-electricsSascha Populoh

18:15 519 Tunable conductivity threshold at polar oxide inter-faces: implications for understanding its originMathilde L. Reinle-Schmitt


20:15 Grillparty

Friday, 22.06.2012, HPH G 1

Time ID ManeP iiiChair: Alberto Morpurgo, Uni Genève

11:00 521 Magnetoplasmons and Faraday rotation in graph-eneA. B. Kuzmenko (i)

11:30 522 Engineering Dirac points with ultracold fermions in a tunable optical latticeDaniel Greif

11:45 523 Transport through graphene on SrTiO3Nuno Couto


ManeP iVChair: Frédéric Mila, EPFL

13:30 531 Studying the physics of disordered bosons with dis-ordered magnetic insulatorsTommaso Roscilde (i)

14:00 532 Observation of a quantum critical point in the heavy fermion antiferromagnet CeRhSi3Nikola Egetenmeyer

14:15 533 Antiferromagnetic spin-S chains with exactly di-merized ground statesFrédéric Michaud

14:30 534 Diagrammatic Monte Carlo for the Hubbard modelJan Gukelberger

14:45 535 Static and dynamic properties of a strong-leg spin ladderDavid Schmidiger

15:00 536 Zero field splitting in the two-dimensional quantum spin liquid PHCCMaximilian Goldmann

15:15 537 Controlled flux penetration in platelet supercon-ductorsRoland Willa

15:30 Coffee Break

ManeP VChair: Andrey Zheludev, ETH Zürich

16:00 541 Spin-Orbital Separation in a Cuprate Spin Chain and Studies of Fe-based Superconductors with Resonant Inelastic X-ray ScatteringThorsten Schmitt (i)

16:30 542 Mapping of electron-hole excitations in a charge density wave system with Resonant Inelastic X-ray ScatteringClaude Monney

16:45 543 Magnetism and orbital physics of the Mott insula-tor LuVO3Markos Skoulatos

17:00 544 Imprinting magnetic information in manganites with X-raysMarios Garganourakis

17:15 END

ID ManeP PoSter

5001 Soft x-ray photoemission measurements on LaAlO3/SrTiO3 and (LaAlO3)x(SrTiO3)1−x/SrTiO3 heterostructuresClaudia Cancellieri

22


5002 Bond disorder in Cu(quinoxaline)X2, X = Cl, BrWolfram E. A. Lorenz

5003 Asymmetric Josephson effect at the interface of non-cen-trosymmetric superconductorsLudwig Klam

5004 Electron-hole instability in TiSe2Gael Monney

5005 μSR investigation of magnetism and magnetoelectric cou-pling in Cu2OSeO3Aleander Maisuradze

5006 Multiscaling analysis of intrinsic domain walls in epitaxial BiFeO3 thin filmsBenedikt Ziegler

5007 Phase diagram of epitaxial BiFeO3-LaFeO3 SuperlatticesGijsbert Rispens

5008 Multiplet calculations and X-ray spectra simulations in low symmetry compounds.Anne-Christine Uldry

5009 Field driven ordering in a frustrated spin ladder with bond randomnessErik Wulf

5010 Thermoelectric effect in one-dimensional metallic systems - a model study on the impact of disorder and phononsDaniel Müller

5011 Graphene on Ruthenium: Four hillsIrakli Kalichava

5012 Nanoscale PFM imaging of intrinsic domains in PbTiO3 ul-trathin films.Céline Lichtensteiger

5013 Pressure dependence of optical exitations in tetragonal Sr2VO4Michael Tran

5014 Doping and temperature dependence of STS spectra in Bi2Sr2Ca1Cu2O8+

Thomas B. Amundsen

5015 Scanning tunnelling microscopy/spectroscopy study of La2/3Ca1/3MnO3 thin filmsZoran Ristic

5016 First direct observation of the Van Hove Singularity in the tunnelling spectra of cupratesAlexandre Piriou

5017 Effect of bond disorder on weakly-coupled spin-1/2 antifer-romagnetic Heisenberg chainsMatthias Thede

5018 CVD graphene: effects of the environment and annealing on its doping level and the charge carriers mobilityChristophe Caillier

5019 Nearest-neighbor spin correlations and doublon produc-tion rate by lattice modulation for spin-1/2 fermionic atomsAkiyuki Tokuno

5020 New experimental setup for thermal conductivity measure-ments: stability against quench in industrial Nb3Sn wires fabricated by various techniquesMarco Bonura

5021 Temperature and time scaling of the peak-effect vortex configuration in FeTe0.7Se0.3Marco Bonura

5022 Physical properties of TiSe2 crystals grown by vapour transport technique.Alberto Ubaldini

5023 Bulk insulating states in the Bi2(Se1−xTex)3 solid solution.Alberto Ubaldini

5024 Optical properties of Bi2Te2SeAna Akrap

5025 Interactions between carbon nanotubes and epitaxial Pb(Zr0.2Ti0.8)O3 thin filmsCédric Blaser

5026 Humidity Sensing Properties of Different Bismuth Phos-phate TypesMin Sheng

5027 Optical Measurements of Neodymium and Samarium Nick-elatesJulien Ruppen

5028 Structural study of LaNiO3 heterostructures at the metal-insulator transitionSteven J. Leake

5029 Effect of phase separation and vacancy order on the super-conducting and magnetic properties of RbxFe2−ySe2Steven Weyeneth

5030 The effect of nitrogen incorporation on the thermoelectric properties of EuTiO3 and EuTi0.98Nb0.02O3Leyre Sagarna

5031 Semiclassical theory of the 1/2 magnetization plateau of the J1-J2 model on the square latticeTommaso Coletta

5032 Infrared Spectroscopy on Gated Tri-layer GrapheneNicolas Ubrig

5033 Hysteresis in the temperature dependent electronic struc-ture of NdNiO3: A photoemission studyZuzana Vydrová

5034 Mixed crystals from the quantum magnets Ba3Cr2O8 and Sr3Cr2O8Henrik Grundmann

5035 Influence of different synthesis methods on thermoelectric properties of Ti0.33Zr0.33Hf0.33NiSn half-Heusler compound with emphasis on thermal conductivity measurementsKrzysztof Galazka

5036 Self-consistent structure of a domain wall in Sr2RuO4Adrien Bouhon

5037 Realization of a thermal LC-circuitOlaf Bossen

5038 Competition between columnar and plaquette order in the fully frustrated transverse field Ising model on the square lattice.Sandro Wenzel

5039 Hybridization gap and anisotropic far-infrared optical con-ductivity of URu2Si2Julien Levallois

5040 The influence of defects in the quasi-2D CDW compound 1T-TiSe2Clément Didiot

5041 A Thermoelectric Study on the Electron Gas at the LaAlO3/SrTiO3 InterfaceDanfeng Li

5042 Disorder in a quasi-two-dimensional quantum spin liquidDan Hüvonen

5043 Resonant inelastic x-ray scattering on a quasi-one-dimen-sional multiferroic cuprate: probing the local magnetic cor-relationsClaude Monney

5044 Critical current of Nb3Sn wires under quasi-hydrostatic ra-dial pressureGiorgio Mondonico

5045 Phase diagram of the EuFe2As2 system with respect to chemical and hydrostatic pressureZurab Guguchia

5046 On Electronic Properties and Superconductivity of Strained High Tc FilmsNathaniel Wooding

5047 Effects of bond disorder in the quantum spin ladder (C5H12N)2CuBr4(1-x)Cl4xSimon Ward

23


5048 Nanoscale studies of electrical conduction in ferroelectric domain walls with insulator coated carbon nanotube tipsYuliya Lisunova

5049 Influence of the Internal Polarizability on the Charge Trans-port Properties in N-Type Organic Single Crystal Field-Ef-fect TransistorsNikolas Minder

5050 Control of the magnetic volume fraction in Co-doped TiO2 films via oxygen vacanciesHassan Saadaoui

5051 Structural and electrical properties of BaTiO3 thin-film ca-pacitorsStephanie Fernandez-Pena

5052 One-dimensional nanolines and single atom chains on Si(001)François Bianco

5053 Frustration and disorder in a 1D spin ladder at high mag-netic fieldsToni Shiroka

5054 Tuning superconductivity and magnetism in FeySe1−xTexMarkus Bendele

5055 Superconductivity Driven Imbalance of the Magnetic Do-main Population in CeCoIn5Simon Gerber

5056 Ultrafast X-Ray Nanowire Single-Photon Detectors and Their Energy-Dependent ResponseKevin Inderbitzin

5057 Magnetic phase transitions in PbBxB’1−xO3 (B = Fe, andB’ = Nb, Ta)Shravani Chillal

5058 Differences in Chiral Expression: Racemic and Enantiopure Heptahelicenes on Various Metal SurfacesJohannes Seibel

5059 The Luttinger liquid theory of molybdenum purple bronzePiotr Chudzinski

5060 Temperature-Dependence of Detection Efficiency in NbN and TaN SNSPDAndreas Engel

5061 Electronic Properties of Single-Crystal Organic Charge-Transfer Interfaces probed using Schottky-Gated Heter-ostructuresIgnacio Gutierrez Lezama

5062 Crossover from Coulomb blockade to quantum-Hall effect in suspended graphene nanoribbonDongKeun Ki

5063 Doping dependence of the pseudogap phase in La-based cupratesChristian Matt

5064 Soft-X-Ray ARPES: From Three-Dimensional Materials to HeterostructuresVladimir N. Strocov

5065 Conduction at domain walls in insulating Pb(Zr0.2Ti0.8)O3Iaroslav Gaponenko

5066 Fluctuations of one-dimensional interface in the directed polymer formulation: role of a finite interface widthElisabeth Agoritsas

5067 Local study of the electronic and structural properties of colloidal semiconductor nanocrystalsMaria Longobardi

5068 Pressure dependence of the penetration depth in CeCoIn5 studied by muon spin rotationLudovic Howald

5069 Hexagonal InMnO3 - An Outsider Among The Family Of Mul-tiferroic Hexagonal ManganitesMartin Lilienblum

6 NCCR Nano

i. nanoMechanicS

Thursday, 21.06.2012, HCI G 3

Time ID nanoMechanicS

Chair: Martino Poggio, Uni Basel

13:30 601 Coherent coupling of light and mechanical motionEwold Verhagen (i)

14:00 602 Stable "ring-like" Ag clusters on Si(111)-(7×7): volt-age dependency study of the scanning tunneling microscopy apparent topographyNicolas Mariotti

14:15 603 Detection of cantilever thermal motion and feed-back cooling using a quantum point contactMichele Montinaro

14:30 604 Entering the nonlinear regime with mechanical res-onators made from nanotubes and grapheneAlexander Eichler (i)

15:00 605 The Lateral Resolution of the near-tip scanning electron microscopy.Danilo Pescia

15:15 606 Prospects and challenges for atomic force micros-copy in molecular structure recognitionBruno Schuler

15:30 Coffee Break

16:00 607 Non-contact friction measurements by means of Atomic Force Microscopy (AFM) operated in pen-dulum geometryMarcin Kisiel (i)

16:30 608 NanoXAS - Combining Scanning Probe and X-Ray Microscopy for NanoanalyticsNicolas Pilet

16:45 END


20:15 Grillparty

ii. nanoPhotonicS & Varia

Thursday, 21.06.2012, HCI G 7

Time ID nanoPhotonicS iChair: Olivier Martin, EPFL

13:30 621 Towards time-resolved 3D imaging and probing with Photonic Force MicrospectroscopySylvia Jeney (i)

14:00 622 Study of the Optical Transport within Plasmonic Nano- and Sub Nano-metric JunctionsBanafsheh Abasahl

14:15 623 Nanoscale Chemical Analysis by Tip-Enhanced Ra-man Spectroscopy: Recent Developments and Ap-plicationsThomas Schmid (i)

14:45 624 Gold Photoluminescence in Nanoscale AntennasToni Fröhlich

15:00 625 3-Dimensional Computational Nano-Optics - With a Focus on Fabricated StructuresBenedikt Oswald (i)

15:30 Coffee Break

VariouS nanotoPicS

Chair: NN

16:00 631 Imaging the charge distribution within a single mol-eculeFabian Mohn (i)

24


16:30 632 Chemical sensing with silicon nanowire field-effect transistorsRalph Stoop

16:45 633 Combining SFM & ToF-SIMS: a new route to access chemical information at the nanoscaleLaetitia Bernard

17:00 634 Progress in electron beam generation for Near Field-Emission Scanning Electron MicroscopyDanilo Andrea Zanin

17:15 635 New Developments in Near Field-Emission Scan-ning Electron MicroscopyLorenzo G. De Pietro

17:30 636 Electrostatic characterization of Near Field-Emis-sion Scanning Electron MicroscopyHugo Cabrera

17:45 637 Resonances arising from hydrodynamic memory - The Color of Brownian motionMatthias Grimm

18:00 638 Graphane formation and patterning by pure hydro-gen low temperature plasma exposureBaran Eren

18:15


Friday, 22.06.2012, HCI G 7

Time ID nanoPhotonicS iiChair: Olivier Martin, EPFL

13:30 641 Plasmonic Promises: Single Molecule Sensing, Electrochemistry, Nanowire Electronics, Strain Vis-ualization, and InterferometryJanos Vörös (i)

14:00 642 Periodic nanogap arrays for surface enhanced spectroscopy: modeling and performanceThomas Siegfried

14:15 643 Targeting cells with gold nanoparticlesSara Peters (i)

14:45 644 Electron emission from optically excited metallic nanotipsAnna Mustonen

15:00 645 Organic LEDsBeat Ruhstaller (i)

15:30 END, Coffee Break

iii. nanobioPhySicS

Friday, 22.06.2012, HCI J 7

Time ID nanoPbioPhySicS

Chair: Georg Fantner, EPFL

13:30 661 Nanophotonics and Nanoelectronics Tools for Single Molecule BiophysicsAleksandra Radenovic (i)

14:00 662 Investigating Skin Cancer with Nanomechanical BiosensorsFrançois Huber

14:15 663 Optimization of DNA hybridization efficiency by pH-driven nanomechanical bendingJiayun Zhang

14:30 664 Study of DNA relaxation on mica using AFM with further automatic tracingAndrey Mikhaylov

14:45 665 Direct Visualization of Lipid Membrane Dynamics Using High-Speed Atomic Force Microscopy (HS-AFM)Jonathan D. Adams

15:00 666 Microfabricated Membrane Surface Stress Sensors for Medical Breath TestingHans Peter Lang

15:15 END

15:30 Coffee Break

ID nano PoSter

671 Optomechanical Coupling of Ultracold Atoms and a Mem-brane OscillatorMaria Korppi

672 Friction anisotropy investigations: Measurements on the an-isotropic surface of an organic layer compound crystalGregor Fessler

673 Near Field-Emission Scanning Electron MicroscopyPeter Thalmann

674 Electron Beam Properties of Large Double Gate Field Emit-ter Arrays with an Optimized Collimation Gate Electrode Ge-ometryPatrick Helfenstein

675 Fabrication and characterization of tunable plasmonic na-nostructures for biosensingOlivier Scholder

676 Study of biomolecular interactions using photonic crystal surface waves (PC SW) optical sensor.Tatyana Karakouz

7 NCCR MUST

Friday, 22.06.2012, HPH G 2

Time ID MuSt iChair: Lukas Gallmann, ETH Zürich

11:00 701 Probing electronic valence shell dynamics in mol-eculesHans Jakob Wörner (i)

11:30 702 Electron ionization times measured with the atto-clockRobert Boge

11:45 703 Attosecond Time-Gated Absorption and EmissionJens Herrmann

12:00 Postersession (continued), LunchbuffetPublic Tutorial see p. 15

MuSt iiChair: Thomas Feurer, Uni Bern

13:30 711 Optimal Dynamic Discrimination of Free Amino Ac-ids and Small PeptidesJean-Pierre Wolf

13:45 712 Dynamic probe concept for studying aggregation of organic dye molecules at liquid/liquid interfaces by femtosecond second harmonic generation tech-niqueMarina Fedoseeva

14:00 713 Breaking Down the Problem to Understand the Photophysics of Conjugated PolymersNatalie Banerji

14:15 714 Investigation of low frequency vibrations using dis-persed femtosecond – DFWMGregor Knopp

14:30 715 Multidimensional IR spectroscopy of waterPeter Hamm (i)

25


15:00 716 Measuring nonadiabaticity of molecular quantum dynamics with quantum fidelity and with its effi-cient semiclassical approximationTomáš Zimmerman

15:15 717 Perturbative Treatment of the Up-Conversion De-tection of Pulse-shaped Entangled Photons and ApplicationsChristof Bernhard

15:30 Coffee Break

MuSt iiiChair: Jürg Osterwalder, Uni Zürich

16:00 721 High-harmonic generation from oriented OCS mol-eculesPeter Kraus

16:15 722 A double-sided time-resolved VMI setup with high temporal resolutionYuzhu Liu

16:30 723 Femtosecond dynamics of atomic structure in sol-idsSteve L. Johnson (i)

Chair: Paul Beaud, PSI Villigen

17:00 724 Femtosecond Transient Diffuse Reflectance for Dye-Sensitized Solar CellsElham Ghadir

17:15 725 p-Conjugated Donor-Acceptor Systems as Metal-Free Sensitizers for Dye-Sensitized Solar Cell Ap-plicationsMateusz Wielopolski

17:30 726 Probing interfacial electron transfer dynamics in the attosecond time domainLuca Castiglioni

17:45 727 Atomic motion of a coherent phonon observed in a charge and orbitally ordered manganiteAndrin Caviezel

18:00 728 Electron dynamics in a quasi-1-dimensional topo-logical metal: Bi(114)Matthias Hengsberger

18:15 729 Laser induced coherent structural dynamics of the Heusler alloy Ni2MnGaSimon O Mariager

18:30 730 Non-retarded pairing interaction in a high-Tc cu-prate from coherent charge fluctuation spectros-copyFabrizio Carbone (i)

19:00 END

ID MuSt PoSter

741 Direct High Harmonics Pulse Shaping in the XUVJean-Pierre Wolf

742 High-Power Mid-infrared Femtosecond Laser Source Based On Parametric TransferC. Heese

743 Stereochemistry of C4 dicarboxylic acids on Cu(110)Chrysanthi Karageorgaki

744 Beating the efficiency of both quantum and classical simula-tions with semiclassicsCesare Mollica

745 Confocal fs-CARS measurement of nano-particles in epi-directionGregor Knopp

746 Probing the longitudinal momentum spread of the electron wave packet at the exit pointAlexandra Landsman

747 Accelerating the calculation of time-resolved electronic spectra with the cellular dephasing representationMiroslav Šulc

748 Towards femtosecond dynamics in multiferroicsTeresa Kubacka

749 Photon echo measurements using a frequency doubled cav-ity dumped femtosecond oscillatorVesna Markovic

750 A Combined NIR Transient-Absorption Optical Pump-THz Probe Spectroscopy Study on Charge Carrier Generation Dynamics in Solid State Dye Sensitized Solar CellsJan Brauer

751 Investigation of chemical surface treatment on the charge carrier dynamics in solid-state Dye-Sensitized Solar CellsArianna Marchioro

752 Photoinduced Processes of Small Molecule Organic Photo-voltaicsJelissa De Jongh

753 Photoelectron Diffraction on SnPc/Ag(111)Michael Greif

754 Effects of the finite length of the pump laser pulse in nona-diabatic quantum dynamics simulations of ultrafast time-resolved spectroscopyAurélien Patoz

755 Accelerating calculations of ultrafast time-resolved elec-tronic spectra with various high order split-operator algo-rithmsMarius Wehrle

756 High-harmonic spectroscopy of isoelectronic molecules: electronic structure and multielectron effectsAlisa Rupenyan-Vasileva

757 Actively Stabilized Attosecond InterferometerMartin Huppert

758 Ultrafast time-resolved photoelectron spectroscopy of sol-vated systemsInga Jordan

759 Versatile velocity-map-imaging spectrometer for strong-field and attosecond experimentsSamuel Walt

760 Versatile Non Collinear Four-Wave Mixing Set-Up Fully Based on Femtosecond Pulse Shaping for Coherent Elec-tronic SpectroscopyFranziska Frei

761 Field Enhancement in THz nano-structuresFabian Brunner

762 Femtosecond surface second harmonic generation micros-copy to probe adsorbed layers at interfacesDelphine Schaming

763 Time resolved surface second harmonic generation and electron transfer reactions at liquid-liquid interfacesAstrid Olaya

8 NCCR QSIT

Friday, 22.06.2012, HCI G 3

Time ID QSit iChair: Richard Waburton, Uni Basel

11:00 801 Torque Magnetometry of Individual Ni NanotubesDennis P. Weber

11:15 802 Characterization of nano-scale electrical contacts using dynamical Coulomb blockadeKonrad H. Müller

11:30 803 Scanning gate experiments on graphene nanorib-bonsNikola Pascher

26


11:45 804 All Electrical Control and Slowing of Microwaves using Circuit Nano-electromechanicsXiaoqing Zhou


QSit iiChair: Klaus Ensslin, ETH Zürich

13:30 811 Graphene Quantum DotsJohannes Güttinger (i)

14:00 812 Rectification of thermal fluctuations in a chaotic cavity heat engineBjörn Sothmann

14:15 813 Fiber-cavity spectroscopy of quantum wells and charge-controlled quantum dotsJavier Miguel-Sanchez

14:30 814 Supplying cluster states for one-way quantum computingDaniel Becker

14:45 815 Multilevel transport in a three-terminal graphene quantum dotPauline Simonet

15:00 816 Quantum Hall effect in Graphene with supercon-ducting electrodesPeter Rickhaus

15:15 817 Quantum Metrology with a Scanning Probe Atom InterferometerCaspar Ockeloen

15:30 Coffee Break

QSit iiiChair: Matthias Christandl, ETH Zürich

16:00 821 Dark state spectroscopy of a single hole spinJulien Houel (i)

16:30 822 Exploring cavity-mediated long-range interactions in a dilute quantum gasRenate Landig

16:45 823 Density functional theory for static and dynamic properties of atomic quantum gasesLei Wang

17:00 824 Quantum state tomography of 1000 bosons:reduced density matricesMichael Walter

17:15 825 Ultrastrong Coupling of the Cyclotron Transition of a 2D Electron Gas to a THz MetamaterialCurdin Maissen

17:30 END

ID QSit PoSter

841 Electronic transport in ultra-clean carbon nanotube quan-tum dotsStefan Nau

842 Quantum dots in the quantum Hall regimeStephan Baer

843 Progress toward nanoscale magnetic resonance with a "magnet-on-cantilever" force microscopePhani Peddibhotla

844 Tunnel barriers for spin injection into grapheneMatthias Bräuninger

845 A hybrid on-chip opto-nanomechanical transducer for ultra-sensitive force measurementsEmanuel Gavartin

846 Probing charge noise in a semiconductor with laser spec-troscopy on a single quantum dotAndreas Kuhlmann

847 Geometric phase gates for trapped molecular ionsMatthias Germann

848 Cold collisions in an ion - atom hybrid trapFelix Hall

849 Design and development of a surface electrode ion trap for sympathetically cooled molecular ionsArezoo Mokhberi

850 Density Matrix Renormalization Group for Optical LatticesMichele Dolfi

851 In search of operational quantities for characterizing large quantum systemsNormand Beaudry

852 On the Optimality of Work Extraction in Small Thermody-namical SystemsPhilippe Faist

9 Earth, Atmosphere and Environmental Physics

Thursday, 21.06.2012, HCI D 8

Time ID i: atMoSPhere and geohySicS

Chair: Stéphane Goyette, Uni Genève

13:45 901 Ionising radiation in the EnvironmentChristophe Murith (i)

14:15 902 Influence of Galactic Cosmic Rays on the atmos-pheric composition and temperatureMarco Calisto

14:30 903 Laser-induced aerosol generation in airMassimo Petrarca

14:45 904 Wind gusts parametrization methods for winter storms in Switzerland with the Canadian Regional Climate ModelCharles-Antoine Kuszli

15:00 905 A Study of Interface Effects Between Porous and Double Porous MediaEduard Oberaigner

15:15 906 Fiber bundle models for granular shearing and acoustic emissions during landslide initiationDenis Cohen

15:30 Coffee Break

ii: reSourceS (geology, MaterialS, biofuelS, energy & lca)

Chair: Antoine Pochelon, EPFL-CRPP

16:00 911 Deep structure of the Swiss Plateau from seismic-wave sounding: a new 3D seismic model of the Swiss Molasse BasinFrançois Marillier (i)

16:30 912 Scarce metals - Applications, supply risks and need for actionPatrick A. Wäger (i)

17:00 913 Roundtable on Sustainable Biofuels: Ensuring Bio-fuels Deliver on their PromisesSebastien Haye (i)

17:30 914 Energy resources, energy choices and life cycle assessmentAndrew Simons (i)

18:00 END


20:15 Grillparty

27


Aussteller - ExposantsAgilent Technologies, CH-4052 Basel

www.agilent.com

attocube systems AG, DE-80539 Münchenwww.attocube.com

Bruker AXS GmbH, DE-76187 Karlsruhewww.bruker.com

DECTRIS Ltd, CH-5400 Badenwww.dectris.com

Dyneos AG, CH-8307 Effretikonwww.dyneos.ch

EPL-IOP, UK-Bristolwww.iop.org

GMP SA, CH-1020 Renenswww.gmp.ch

Hiden Analytical Ltd., UK-Warrington, WA5 7UNwww.hidenanalytical.com

HORIBA Jobin Yvon GmbH, DE-64625 Bensheimwww.horiba.com/de/scientific

Hositrad Deutschland Vacuum Technology,DE-93047 Regensburg

www.hositrad.com

MaTecK GmbH, DE-52428 Jülichwww.mateck.de

Meili-Kryotech, CH-7433 Donatwww.kryotech.ch

NanoScan AG, CH-8600 Dübendorfwww.nanoscan.ch

Oxford Cryosystems Ltd, UK-Long Hanborough, OX29 8LNwww.oxcryo.com

Schäfer-Tec AG, CH-3422 Kirchberg BEwww.schaefer-tec.com

SENTECH GmbH, DE-82152 Krailingwww.sentech-sales.de

Stoe & Cie GmbH, DE-64295 Darmstadtwww.stoe.com

Swiss Vaccum Technologies S.A., CH-2022 Bevaixwww.swissvacuum.com

TECO René Koch, CH-1807 Blonaywww.teco-rene-koch.com

VG Scienta, UK-Hastings, East Sussex, TN38 9NNwww.vgscienta.com

VACOM GmbH, DE-07749 Jenawww.vacom.de

Zurich Instruments, CH-8005 Zürichwww.zhinst.com

KurzmitteilungenPatenschaft für Maturaarbeiten

Die Akademie der Naturwissenschaften Schweiz (SCNAT) sucht ExpertInnen, die an 4 Halbtagen im Jahr Maturaar-beiten von Mittelschülern in allen naturwissenschaftlichen Fächern (Biologie, Chemie, Geowissenschaften, Informatik, Mathematik, Physik) betreuen wollen.

Hauptziel der Initiative «Patenschaft für Maturaarbeiten» ist es, die Begeisterung für naturwissenschaftliche Berufe zu wecken und den GymnasiastInnen einen Blick in die Be-rufswelt zu ermöglichen. Dieses Angebot bietet den Schüle-rInnen die einmalige Möglichkeit, mit Wissenschaftern von Hochschulen oder aus der Industrie in Kontakt zu treten, spezifische Messgeräte zu benutzen und Forschungsluft zu schnuppern. Die Jugendlichen investieren viel in diese Ar-beiten (ungefähr 1 Halbtag/Woche während eines Jahres) und lernen gleichzeitig die verschiedenen Karrieremöglich-keiten in den Naturwissenschaften kennen.

Im 2011 hat die SCNAT beschlossen, angelehnt an die Patenschaften ein neues Angebot im Bereich Nachwuchs-förderung zu entwickeln. Wir haben festgestellt, dass die Schulen regelmässig ReferentInnen suchen, die aus ihren Forschungsgebieten berichten möchten. Es soll deshalb eine Liste mit ExpertInnen geführt werden, die bereit sind, ihre Arbeit SchülerInnen der Sekundarstufe II (15 – 18 Jahre alt) vorzustellen.

Weitere Informationen: www.maturitywork.scnat.ch

Ernennung von SATW-Mitgliedern

Die Schweizerische Akademie der Technischen Wissen-schaften (SATW) hat an ihrer Mitgliederversammlung am 26. April 2012 folgende SPG Mitglieder zu ordentlichen Einzelmitgliedern ernannt:Dr. Rolf Allenspach, Dr. Pierangelo Gröning und Dr. Thomas von Waldkirch.Der SPG-Vorstand freut sich über die ehrenvolle Ernennung und beglückwünscht die Kollegen aufs herzlichste.

Joint EPS-SIF International School on Energy

New Strategies for Energy Generation, Conversion and Storage

30 July - 4 August 2012, Villa Monastero, Varenna (Lake Como)Directors: L. Cifarelli (Università di Bologna), F. Wagner (Max-Planck-Institut für Plasmaphysik, Greifswald), D. S. Wiersma (LENS, Firenze)Contact person: M. Burresi - [email protected] information:http://en.sif.it/activities/energy_school/2012

28


Progress in Physics (28)

In der Reihe "Progress in Physics" berichten Physikerinnen und Physiker über ihre Aktivitäten an schweizerischen Hoch-schulen und Industrien. Jedes SPG - Vorstandsmitglied kommt zyklisch an die Reihe, einen Artikel zu acquirieren. Mit dieser Vorgangsweise wird zwar für eine gewisse thematische Breite gesorgt, aber eine Sichtung der bisherigen Beiträge zeigt, dass aus der Industrie bislang wenig kam. Das heisst aber nicht, dass die Industrie an Forschungsergebnissen nicht interessiert sei, aber sie müssen eine erste Umsetzbarkeit erkennen lassen. Wie man Innovation und Realisierung näher zusammenbringt, ist Anliegen des SATW-Forums, über dessen jüngste Veranstaltung im November 2011 im folgenden berichtet wird.

SATW Forum "Advanced Optoceramics"

Bernhard Braunecker und Rolf Hügli (SATW)

In der 2010 gestarteten Reihe des "SATW Forums" sollen neue Erkenntnisse über ein aktuelles Technologiethema im kleinen Kreis von Experten besprochen werden. Die jeweils behandelte Technologie sollte im Ansatz neuartig, jedoch physikalisch im Labor verifiziert sein, und sie sollte noch einer industriellen Umsetzung harren, aber bereits ein at-traktives Marktpotential für Produkte erkennen lassen. Von - zumindest in dieser Phase - minderer Bedeutung ist, wenn der Weg von der Laborverifizierung zum industriellen Produkt bislang noch als zu risikoreich eingeschätzt wird, da sich gerade dies durchaus als Wettbewerbsvorteil für die hiesigen Hochschulen und Industrien erweisen könnte.Die Diskussion im Forumskreis soll primär zeigen, ob auf Seiten von Hochschule und Industrie nicht nur fachliche Kompetenz, sondern auch ein gemeinsames Interesse an einer Weiterentwicklung der Technologie zur Produktreife gegeben ist, und wie die Chancen einer solchen Realisie-rung beurteilt werden? Letzten Endes soll ausgelotet wer-den, ob durch eine gemeinsame Aktion Grundlagen gelegt werden können, um neue, hochwertige Arbeitsplätze in der Schweiz mittel- bis langfristig zu schaffen.Bei der Auswahl der Themen sollte deshalb darauf geachtet werden, dass die Technologie trotz ihrer Neuartigkeit auf ei-ner gewissen Tradition in der Schweiz wie Miniaturisierung, Höchstpräzision, Umweltverträglichkeit aufbauen kann, um politische Akzeptanz und Verständnis in der Öffentlichkeit zu finden. Zudem erscheint sinnvoll, dass die Themen im evolutionären Sinne eine Weiterführung früherer Aktivitäten wie zum Beispiel eine Umsetzung der Nanotechnik sind.

Über sie wurden in der Schweiz in den vorangegangenen Jahren sowohl auf akademischer wie industrieller Seite ge-nügend neue Erkenntnisse prinzipieller Natur gewonnen, um die bereits angesprochenen Risiken bei einer Weiter-führung zu minimieren.Die Forumsreihe fokussiert sich somit auf drei Kernanliegen der SATW, nämlich der Früherkennung von Technologien, der Netzwerkbildung und der Gewinnung optimaler Akzep-tanz der Technologie durch die Öffentlichkeit, was im We-sentlichen durch eine frühzeitige Auseinandersetzung mit ethischen Grundsätzen geschieht.

OptokeramikenAls Thema des zweiten Forums wurde Advanced Optoce-ramics gewählt. Optokeramiken gehören zur Klasse der oxidisch-mineralischen Werkstoffe, die ein breites Applika-tionsspektrum von Hochspannungsisolatoren bis zu Medi-zinalanwendungen abdecken. 1987 erhielten J. G. Bednorz und K. A. Müller vom IBM Forschungszentrum in Rüschlikon den Nobelpreis für ihre Pionierarbeiten an auf Oxidkeramik basierenden Hochtemperatur-Supraleitern. In der Schweiz werden Keramiken schwerpunktsmässig bei der EMPA, an beiden ETHs, aber auch in der Industrie behandelt.Generell zeichnen sich diese Werkstoffe dadurch aus, dass sich durch gezielte Dotierung der Keramikmatrix mit Fremd-partikeln die mechanischen, elektrischen, thermischen und optischen Eigenschaften verändern lassen. Das geschieht über einen mehrstufigen und die Nanotechnik einbezie-henden Herstellprozess. Man zermahlt die Werkstoffe zu

Im Abbe-Diagramm liegen links unten die Gläser mit niederer Brechzahl und schwacher Dispersion, rechts oben die hochbrechenden, aber leider auch mit starker Dispersion versehenen Gläser. Für den Optikdesign ideal wären Gläser in der Gegend des Bildes von Ernst Abbe. Nur beginnen die Gläser nahe einer magischen Li-nie auszukristallisieren, was sie technisch unbrauchbar macht. Anstatt nun gegen die Kristallisierung vergeblich anzukämpfen, macht es mehr Sinn, gleich auf Keramiken zu setzen und diese in ihren optischen Eigenschaften gleichwertig zu Gläsern zu machen. Die Blasen im Dia-gramm zeigen Bereiche von Optokeramiken, wo in guter optischer Qualität bereits Prototypen vorliegen, und die sich in ihrer Transmission, in den Teildispersionen, etc. voneinander unterscheiden.

29


Nanopulver, dotiert und kommt über geeignete Press- und Sinterprozesse zurück zu makroskopisch handhabbaren Proben. Da die Dopingrate beim heterogenen Nanopulver-Konvolut deutlich grösser sein kann als beim Einkristall, sind höhere Effizienzen bei bestimmten Materialeigen-schaften zu erwarten.Da jedoch das Thema "Keramik" in seiner vollen Breite eine Forumsveranstaltung überfordern würde, wurde das Thema auf die Untermenge der optischen Keramiken beschränkt. Diese, nicht zu verwechseln mit Glaskeramiken, zeigen eine hohe optische Transparenz, sind also rein äusserlich von hochwertigen optischen Glasscheiben nicht zu unter-scheiden. Sie zeigen aber neben den für Keramiken typisch guten mechanischen und thermischen Eigenschaften auch weitere, für den Bau von Optikinstrumenten interessante optische Werte. Erwähnenswert sind hohe Brechzahlen, aussergewöhnliches Dispersionsverhalten und vor allem eine nutzbare Transmission vom visuellen bis in den 5-6 μm Spektralbereich, während Gläser nur bis etwa 2 μm eingesetzt werden können. Gerade für medizinische An-wendungen mit dem Erbiumlaser bei 3 μm sind somit neue Möglichkeiten denkbar.

Teilnehmerkreis und SymposiumsablaufDie Veranstaltung wurde am 24. November 2011 zusam-men mit der EMPA an ihrem Standort in Dübendorf durch-geführt. Die Organisatoren waren J. G. Bednorz / IBM, B. Braunecker / SATW, P. Gröning & T. Graule / EMPA und H. P. Herzig / EPFL. Die 30 Teilnehmer kamen von Ceramet, EMPA, EPFL, ETHZ, Fisba, IBM, Lasag, Leica Geosystems, Lonza, Metoxit, Micos, RUAG Space, Schott Forschungs-zentrum Mainz, Schott Schweiz, Silitec, Swissoptic, Swiss-LaserNet, Trumpf und Uni Bern. Das Symposium war zwei-teilig gegliedert. Nach sechs einführenden Kurzreferaten wurde in der Teilnehmerrunde diskutiert, welche Auswir-kungen die Ergebnisse für die Schweiz haben könnten?

Thematische StrukturierungDie Referate wurden in drei Blöcken präsentiert. Im ersten Teil berichtete E. Pawlowski / Schott über den neuesten Stand der Herstellung von Schott-Opto-Ceramic Proto-typen SOC. Anschliessend B. Reiss / Swissoptic über Er-gebnisse bei der Oberflächenbearbeitung verschiedener SOC - Proben mit modernen CNC-Maschinen und schliess-lich B. Braunecker (früherer Entwicklungsleiter - Optik bei Leica Geosystems), welche neuen Optiksysteme denkbar wären, wenn es die Materialien kommerziell gäbe. Im zwei-ten Teil erläuterte T. Graule / EMPA die hohen Ansprüche und die komplexen Abläufe bei der Materialherstellung, während A. Studart / ETHZ über neueste Forschungsergeb-nisse mit multifunktionalen Keramiken berichtete. Im dritten Teil referierte J. G. Bednorz über eine neue und Aufsehen erregende Methode aus Japan, bei der das zu dotierende Keramikmaterial dünne Polymerfolien sind, die interessante optische Eigenschaften zeigen, aber vermutlich auch für andere Anwendungen im Solarbereich oder für Batterien geeignet sein könnten.

FazitDie Veranstaltung zeigte, dass der vorgestellte Prozessan-satz, der höhere Dopingraten des zu Nanopulver verarbei-teten Trägermaterials mit "intelligenten" Fremdatomen wie Seltenen Erden ermöglicht, nicht nur zu verbesserten ak-

Abstracts der ReferateFabrication & characterisation of transparent ceramics for novel applications, E. Pawlowski, Schott AGAbout 20 years ago the first development of transparent ce-ramic started, finally achieving poly-crystalline ceramic mate-rials for laser and optical applications. It was demonstrated, that ceramic materials could overcome the main technical pro-blem of light scattering. The established nano-powder vacuum sintering process at SCHOTT shows good potential for mass fabrication of multi-composite ceramic materials with different dopant concentrations. In comparison to conventional transpa-rent materials optoceramics offer further benefits, which lead to a multiplicity of new applications like optical, laser, solid state lighting or scintillation. Apart from better mechanical properties and special optical properties, higher rare-earth doping levels than single crystals can be achieved, which lead to a higher conversion efficiency combined with small temperature and concentration quenching effects. In our talk we will discuss the fabrication process, the realized materials and the different ap-plications of optoceramics.

CNC machined optics, B. Reiss, Swissoptic AGSwissoptic as a leading manufacturer of advanced optical com-ponents and systems will report about the surface treatment of glass and ceramic optics with modern CNC machines and other deterministic technologies. One exciting example is the production of monolithic components, i.e. multifunctional com-ponents out of one piece of glass.

OC materials for lens design, B. Braunecker, SATWBased on the preliminary optical data of various prototypes of Schott Optoceramics (large refractive index, large anomalous dispersion, speckle free transmission, etc.), their impact on the design of optical systems for imaging, projection, medicine, space, etc. will be discussed.

The challenge of failure free nanopowder processing,T. Graule, EMPAAggregate free synthesis and agglomerate free processing of nanopowders is achieved by advanced powder synthesis as well as colloidal processing techniques. The main issue is to overcome Van der Waals attraction forces by surface treatment and high energy dispersion techniques. Different approaches to solve the problem of aggregation and especially agglomeration are demonstrated.

Magnetic control of non-spherical ceramic particles in fluid suspensions, André R. Studart, Complex Materials, Depart-ment of Materials, ETH ZürichWe present a method to deliberately control the orientation of non-spherical nonmagnetic ceramic particles in fluid suspen-sions using magnetic fields as low as 1 milliTesla. To achieve magnetic response, the non-spherical particles are coated with minor contents of magnetic nanoparticles (<0.01 Vol %). This simple approach might be used for the preparation of polycry-stalline ceramics and composite materials with anisotropic op-tical, electrical, magnetic and mechanical properties.

Super hybrid materials, J. G. Bednorz, IBMWe will present a new method, developed by T. Adschiri (Toho-ku University, Sendai, Japan). By using supercritical fluids from metal salts and organic molecules, oxide nanoparticles can be produced with an organic modified surface. These organic-in-organic hybrid nanocrystals, having a high affinity to organic solvents and polymers, can be used to produce flexible ceramic films with a high filling factor. So far flexible superhybrid mate-rials with high refractive index, high thermal/low electrical con-ductivity or magnetic particles could be manufactured, showing the high potential of the new fabrication method.

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Progress in Physics (29)

Understanding exchange bias in thin films

Miguel A. Marioni, Sara Romer, Hans J. Hug 1

Empa, Swiss Federal Institute for Materials Testing and Research, CH-8600 Dübendorf1 Also at: Institute of Physics, Universität Basel, CH-4056 Basel

Every computer hard-drive and many magnetic sensors contain a thin-film device using the GMR or TMR effect. In it, the resistance from a stack of thin films is made to depend on the relative orienta-tion of different magnetic layers’ magnetization, of which one serves as a reference and retains its direc-tion. Fixing the magnetization is ac-complished with exchange-bias. Not surprisingly, the effect has re-ceived much attention throughout the history of magnetic recording and sensor design. Perhaps it is a surprise, then, that so much remains unknown about exchange-bias after half a century since its discovery.

Principles of the exchange bias effectExchange-biasing manifests macroscopically as a lateral shift of size Hex of the hysteresis loop (Fig. 1 (a); occasion-ally there is an accompanying vertical shift Mshift as well.). It occurs if a sample with at least one ferromagnet (F) / antif-erromagnet (AF) bilayer (e.g. in Fig. 1 (b)) is cooled through the Néel temperature (TN) of the antiferromagnet. It is gen-erally believed that (local) magnetization of the ferromagnet (F) layer (locally) generates pinned uncompensated spins (pUCS) in the AF layer that are coupled to the F layer. An obstacle to understanding the exchange bias effect is that only a subset of the UCS (those pinned, and coupled to the ferromagnet) are responsible for it [1]. The experimen-tal method and preparation may affect these subsets in

distinct ways and an interpretation of UCS measurements must take this into account.

Experimental Methods to measure uncompensated pinned spinsReflectometry experiments using polarized neutrons or circularly polarized X-rays as probes have been used to access UCS sub-systems and to map out their thickness distribution. Both methods fit proposed model descriptions of these distributions to the experimental data. Neutron-based techniques can unambiguously determine the rela-tive orientation of the UCS of the various sub-systems and the F-spins. To accomplish this X-ray-based experiments require, in addition, specifying magneto-optical constants of the atomic species carrying the spin in the AF. Recent

Figure 1: (a) Schematic hysteresis loop of an exchange-biased thin magnetic film. (b) Thin film multilayer structure with perpendicular magnetization used for MFM studies of exchange bias. (c) High resolution TEM image of the film structure of (b), highlighting the CoO layer (black arrow) and one grain boundary (white arrow).

M(H)

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Hex

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F

Si

Pt

Pt

×20

(c)(b)(a)

tiven (Laser-) und passiven (Linsen-) Optiksystemen führt, sondern auch zu höheren Effizienzen bei Röntgendetek-toren und LED-Lichtquellen. Die erforderlichen technischen Herstell- & Bearbeitungsprozesse sind zweifelsohne noch herausfordernd, aber mit dem in der Schweiz vorhandenen Wissen bei EMPA und den teilnehmenden Firmen durchaus machbar.Die an den ETHs betriebene Forschung an multifunktio-nalen Werkstoffen ist höchst aktuell, da durch geeignete Behandlungsmassnahmen Keramiken nicht nur wie Halb-leiter in ihren photonischen Eigenschaften eingestellt wer-den können, sondern zusätzlich noch in den mechanisch-thermischen Parametern. Schliesslich wies die von J. G. Bednorz aufgezeigte Methode der Massenproduktion do-tierter Polymere auf eine kostengünstige Mannigfaltigkeit an Anwendungen hin.

Die Veranstaltung wurde von den Teilnehmern mehrheitlich mit "sehr gut" beurteilt und scheint somit einem Bedürfnis entsprochen zu haben. Während die Industrievertreter die Informationen über die Technologiefortschritte begrüssten, bekamen die Hochschulvertreter in der Diskussionsrunde wertvolle Hinweise über mögliche Anwendungsgebiete. Es zeigte sich, dass verschiedene Firmen sich bilateral über ihre Intentionen und Fortschritte austauschen wollen, und es wurde von nahezu allen Teilnehmern der Wunsch nach einer Diskussionsplattform und einer Folgeveranstaltung geäussert.

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results have also stressed the influence on XMLD (X-ray Magnetic Linear Dichroism) signals of the orientation of AF spins relative to the crystallographic axes.Reflectometry techniques cannot, however, reveal the lateral distribution of UCS. This very important aspect of exchange bias characterizations is accessible with other (complementary) techniques. Among these, photoemission electron microscopy (PEEM) with circular and/or linearly polarized X-rays has revealed a correlation between AF do-mains and F-domains, the formation of new chemical phas-es at the AF/F interface with magnetic moments parallel to those of the F, and induced ferromagnetic moments at the AF/F interface. But PEEM microscopes have to-date not attained lateral resolutions on the length scale of grains-sizes of typical polycrystalline AF materials, important for applications. Note that PEEM experiments require the ap-plied magnetic field to be zero or near-zero, and accord-ingly cannot distinguish pinned from non-pinned UCS of the AF directly. In fact, only a small part of the net moment induced locally by the F in the AF consists of pinned UCS, which are difficult to isolate from the rest with present-day PEEM sensitivities.

In contrast to XMCD-PEEM, XMCD (X-ray Magnetic Cir-cular Dichroism) holography is a lens-less imaging meth-od and hence allows the application of arbitrary magnetic fields. Recently, element-selective soft x-ray holography and spectroscopy measurements have been used to study the evolution of domains in ferromagnetic multilayer of [Pt(1.8nm)Co(0.6nm)]×8 on a Mn80Ir20(5nm) antiferromagnetic layer [2]. Element-specific magnetometry revealed uncom-pensated AF magnetic moments on the Mn and allowed to estimate that about 10% of these moments are pinned and thus are relevant for the exchange bias effect. However, no magnetic contrast could be observed at the Mn L3 edge, so the imaging of the pattern of uncompensated and pinned uncompensated Mn moments was not achieved.A different technique to gain access to the UCS of a system is magnetic force microscopy (MFM). Operated in vacuum, MFM typically measures shifts in the resonance frequen-cy of a cantilever outfitted with a magnetic tip. These are proportional to the magnetic field gradients to which the tip is exposed. Therefore an MFM investigation of sample properties requires a sample with suitable domains gen-erating stray field [3]. In a rough approximation, the MFM

contrast arising from the stray field of a domain pattern in a ferromagnetic thin film with perpendicular magnetization is proportional to the z-component of the magnetic moment areal density [2]. This allows a first estimate of the contrast expected for a domain pattern of pinned uncompensated spins imprinted by a corresponding pattern of ferromag-netic domains. In our recent work [2] the MFM contrast measured above an up/down domain pattern in a CoPt fer-romagnetic multilayer was 46 Hz (Fig. 2 (a)). From the mag-netization of the CoPt-multilayer and its thickness a total magnetic moment areal density of mF

z/A= MCoPt tCoPt = 622 kA/m × 22 nm = 1.37 · 10-2 Am2/m2 is found. Likewise an areal moment density of 4.48 · 10-4 Am2/m2, corresponding to a fully uncompensated CoO AF, would thus generate a frequency shift of 1.5 Hz. Our MFM can easily detect ±0.05 Hz in a reasonable measurement bandwidth of 100 Hz, cor-responding to a scan speed of about 1s/line in a 256 pixel line. This means that the corresponding ±1.49 · 10-5 Am2/m2 are detectable, and hence also about ±3% of a fully un-compensated monolayer.

Assessing the number of pinned uncompensated spins by MFMNot only can MFM image fractions of uncompensated AF spins but it can also be used in applied homogeneous fields. These do not generate a force on the magnetic tip and thus do not give rise to MFM contrast. One can there-fore study the evolution of the F-domain pattern in external fields as shown Fig. 2 (a) and (b) (In prior work up to 7 T were applied [4]).MFM however lacks the element-specificity of XMCD methods, so it cannot distinguish directly between different sources of the stray field, i.e. generated by different atomic species. The contrast observed in the data shown in Fig. 2 (a) and (b) arises predominantly from the stray fields ema-nating from the up/down domain pattern of the F-layer and a small contribution from the imprinted local uncompensat-ed AF moments. However, magnetic stray fields generated the F-layer roughness, as well as by local variations of its thickness or saturation magnetization, could also generate a small MFM contrast. Topography-induced variations of the van der Waals force occurring when the tip of the MFM scans in a plane parallel to the average slope of the sample provide yet another contribution to the measured contrast. Modeling shows that from these last contributions to con-

trast only the van der Waals force-medi-ated topography contribution is relevant. It leads to the grainy appearance of the F-domain contrast (Fig. 2 (a)).

If the F-layer is saturated by applying a sufficiently strong external field, it does no longer generate an MFM contrast. One can easily understand this by not-ing that the stray fields generated by the magnetic poles of the top and bottom surface compensate. In this situation the only remaining source of contrast is the pattern of pinned uncompensated AF moments. Note that if the other con-trast contributions cannot be neglected, the difference of two consecutive MFM measurements performed in positive

Figure 2: High resolution MFM images of the sample of Figure 1 (b) and (c) obtained at constant average tip-sample distance of 13.0±0.5 nm. (a) Large contrast obtained in zero applied fields. (b) In a field of 200 mT the bright domains retract. (c) The ferroma-gnetic layer is saturated at 300 mT. A weak and grainy contrast is retained. This contrast remains unaltered in fields of at least 7 T. A white arrow across Figs. (a) – (c) indicates a particular spot of the film where the retracting bright domain leaves a dark mark in the area it covered at zero field.

H = 0

(a)

46 Hz contrast

H = 0

ntrast

200 mT

(b)

35 Hz contrast

200 mT

ontrast

300 mT

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and negative saturation fields will solely contain the con-trast contribution of the pinned UCS moments [4].

Quantitative MFM on exchange-biased systemsIt is now possible to ascertain the exact relation between pinned uncompensated spins and exchange bias by look-ing at the evolution of ferromagnetic domains over the un-derlaying pattern of pinned uncompensated spins [5]. For example a film of Pt(2nm)/CoO(1nm)/Co(0.6nm)/ [Pt(0.7nm)Co(0.4nm)]x20/Pt(20nm)/Si (Fig. 1 (b) and (c)) can be seen

as the ferromagnetic domains evolve, Fig. 2. Dark areas correspond to parallel tip and sample magnetization; i.e. there is an attractive force and negative frequency shift. Conversely, bright areas correspond to the antiparallel ori-entation and positive frequency shift. F-domains are clearly visible in Figs. 2 (a) and (b), generating a contrast of several tens of Hz. As expected, the area of the bright domains (magnetization opposite to the applied field) diminishes as fields are applied parallel to the dark domain magnetization, as e.g. Fig. 2(b) for 200 mT. Consistent with the saturation

Figure 3: Quantitative analysis of the MFM measurements of the multilayer of Figures 1 – 2. (a) Stack of MFM measurements for zero applied field following the buildup of the magnetic multilayer. The top surface is the MFM measurement of F domains’ contrast. Underneath is the interface with the AF, comprising a distributi-on of UCS, aligning antiparallel to the F-orientation. Because the UCS relevant for exchange bias are the pinned ones, they can be determined from the MFM measurement of a saturated ferroma-gnet (Figure 2 (c)) and the tip-transfer function [7], as indicated

in the scale bar in the Figure. White contours are included in this layer to highlight the position of F-domains. (b) Results for 200 mT following the format of (a). (c) Pinned UCS density disaggregated from either F-domain, at 0 and 200 mT applied fields. The average (negative) magnitude of pinned UCS is larger under the retracted yellow F-domains than their zero field counterparts. (d) Graph sho-wing the correlation between pinned UCS density under a domain and the applied field.

100%

-100%pinUCS

0 mT applied �eld

F

AF

(a) (c)

(d)

(b)

Project F-domaincontours (white)onto AF UCS

200 mT applied �eld

0 100 200 300H (mT)

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ave.

pin U

CS (%

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blue F domains

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33


of the ferromagnet the bright domains have disappeared at 300 mT, Fig. 2 (c). At this and larger fields (up to 7 T) the MFM data reveals a rather irregular pattern with contrast of only 4.4 Hz. Cooling the F/AF system with the F in different initial domain states reveals that the shape of the patterns observed after saturation are governed by the structure of the initial F-domains.

In the same way that the saturated F does not produce a stray field, the uncompensated AF spins which rotate with the F-domains will not be imaged at saturation. The main contrast is thus due to pinned UCS [6]. Using the response function of the MFM tip according to quantitative MFM methods [6] one can obtain the areal moment of pinned uncompensated spins (more specifically the z-component of the areal moment of the pinned UCS projected onto a virtual F/AF interfacial plane) from the Df pattern (Fig. 2 (c)). The result can be seen in Fig. 3 (a). At the AF-F interface a strikingly inhomogeneous distribution of the pinned UCS is revealed. TEM images of the films (Fig. 1(c)) show co-lumnar grains in the film with sizes of the order of 10 nm, placing the observed pinned UCS variations on the same length scale. This pinned UCS distribution also represents an inhomogeneous distribution of ‘‘pinning’’ centers for F-domain motion, leading to the commonly observed EB-induced increase in coercivity.Figures 3 (a) and (b) also show the F-domain contours (white lines) at different fields overlaid to the pinned uncom-pensated AF moment pattern that biases them. From them we see that the pinned UCS in the area initially covered by bright F domains (Fig. 1) is predominantly negative [blue in Figs. 3 (a) and (b)], whereas the area initially covered by dark F domains (Fig. 1) is predominantly positive [yellow in Figs. 3 (a) and (b)]. This local antiparallel alignment be-tween the F magnetization and the pinned UCS suggests antiferromagnetic coupling across the F/AF interface and is consistent with earlier work [2,6,7]. Because the local align-ment is antiparallel to the local cooling field, it can only be the result of exchange coupling.Notice the existence of isolated regions of pinned UCS that do not follow the above trend. They are oriented parallel to the (initial) adjacent F-magnetization, and seem to be cir-cumscribed to areas of the size of single grains of the film (cf. Fig. 1 (c)).More insight can be gained from a quantitative evaluation of the data just discussed.

One can compute the average pinned UCS density (data from Figs. 3 (a) and (b) for the areas under the F-domains, i.e. delimited by the white contours of the figures, as shown in Figs. 3 (c). Under the initial yellow and blue F-domains the average pinned UCS density is ±21.8% of a fully un-compensated monolayer of AF spins. As a magnetic field is applied parallel to the blue F-domains, they expand at the expense of the yellow F-domains. Over the area covered by the retracted yellow F-domains the average pinned UCS is more negative than before the field was applied. Figure 3 (d) shows the average densities of UCS under each domain type as a function of the applied field. A roughly propor-tional relation between the applied field and the average pinned UCS density under the surviving yellow F-domains is apparent.

In Figure 3 (c) small regions can be seen with parallel pinned UCS-F domain alignment at zero field (red arrows). The re-tracting F-domains avoid these regions as they reconfigure in response to the applied field.In other words, at least in the CoO (and MnIr as shown in [2]) Co/Pt perpendicular system pinned UCSs coupling an-tiparallel to the F magnetization stabilize its orientation, i.e. they are biasing, whereas pinned UCSs oriented parallel to the F magnetization have the opposite effect, i.e. they are anti-biasing.These results are a direct observation of the stabilizing ef-fect of (antiparallel) pinned UCS on F domains, and show that a higher pinned UCS density leads to a stronger F do-main pinning, i.e. a higher EB effect.

Concluding remarksThe density of pinned UCS found by MFM agrees well with work on polycrystalline Py/CoO samples estimating the pinned UCS at about 10% of a 1.1 monolayer-thick layer of interfacial Co2+ spins. A decreasing magnetic moment of the FM layer near the interface may explain the somewhat smaller density of pinned UCS observed there. But the high density of pinned UCS requires that the average coupling strength between the pinned UCS and F-spins be much smaller than previously expected, in order to explain the rather small exchange bias field.Without an exhaustive theoretical analysis of the pinned UCS coupling strength and possible variations thereof, we point out that the interface between the AF and the F very likely differs from a chemically sharp interface across which the system goes from F to AF, on account of interdiffusion and interface reconstruction. A similar reconstruction ought to be expected in the CoO/Co interfaces discussed here and may lead to a structurally and chemically disordered interfacial phase, explaining the higher density of pinned UCS and their weaker coupling to the F-spins. Furthermore frustration, as found in spin glass systems, may also lead to weak or indirect coupling between AF UCS and the F-layer. Yet a weak coupling may be a necessary condition for the UCS AF moments to remain pinned to the AF-lattice rather than rotate with the F-moments.

Exchange coupling between different AF grains across their grain boundaries could lead to frustration of the magnetic orientation over grain-size areas, giving rise to the observed anti-biasing effect. Further work to address this issue is un-der way.

[1] I. Schmid, et al. Europhys. Lett. 81, 17001 (2008).[2] C. Tieg et al. Appl. Phys. Lett. 96, 072503, (2010).[3] N. R. Joshi, et al. Appl. Phys. Lett. 98, 082502 (2011).[4] P. Kappenberger, I. Schmid & H. Hug., Adv. Eng. Mater. 7, 332 (2005).[5] I. Schmid, et al. Phys. Rev. Lett. 105, 197201 (2010)[6] P. J. A. van Schendel, H. J. Hug, B. Stiefel, S. Martin & H.-J. Güntherodt. J. Appl. Phys. 88, 435 (2000).[7] P. Kappenberger, et al. Phys. Rev. Lett. 91, 267202 (2003).

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The legacy of Martin GutzwillerLast November, the Faculty of Science of the University of Fribourg awarded the doctor honoris causa to Martin Gut-zwiller, with a threefold motivation: His outstanding contri-butions to theoretical physics, his active interest for science in general and his relations to Fribourg. Reason enough for emphasizing the eminent role Gutzwiller played during the last half century, especially in the two still very active re-search areas of quantum chaos and correlated electrons, as described in some detail below. Special thanks to Michael Berry for his profound analysis of Gutzwiller’s pioneering work in "quantum chaology".

Martin Gutzwiller was born 1925 in Basel. His father was an internationally known professor of law, from 1921 to 1926 at the University of Fribourg, from 1926 to 1936 at the University of Heidel-berg and then, after hav-ing escaped with his family from Germany because of the harassment by the nazis, again in Fribourg from 1937 to 1956. Martin passed his first school years in Heidel-berg. Back to Switzerland, he received his further edu-cation in Trogen and at the

Collège Saint Michel in Fribourg, where he passed the final two years of gymnasium. In 1944 he started studying phys-ics at the University of Fribourg, but then he enrolled at the ETH in Zürich, where he received the diploma in 1949. His diploma work on the magnetic moment of nucleons with vector-meson coupling, supervised by Wolfgang Pauli, un-doubtedly had a strong impact on his view of physics. 45 years later, in a letter to Physics Today (August 1994), he

admits having received “a marvelous education in early field theory”, but at the same time having been frustrated because the problem posed by Pauli could not be handled in a satisfactory way. Thus he pleads for coming back to "down-to-earth physics", instead of "chasing an elusive goal on the basis of abstract models".

After having received his diploma, Martin Gutzwiller worked during one year as an engineer in microwave transmission at Brown Boveri in Baden. In 1951 he moved to the US, where he spent most of the time since. At the University of Kansas he made his Ph. D. studies under the guidance of Max Dresden, on "Quantum Theory of Fields in Curved Space". From 1953 to 1960 he worked on geophysics in a laboratory of Shell in Houston, Texas. A position at the IBM Zurich Research Laboratory, then still in Adliswil, brought him back to Switzerland for three years, but subsequently he settled definitely down in New York. He remained a re-searcher at IBM, from 1963 to 1970 at the Watson Labora-tory and from 1970 to 1993 in Yorktown Heights. He was at the same time Adjunct Professor in Metallurgy at the Co-lumbia University. After his retirement from IBM he became an Adjunct Professor at the Yale University.

Martin Gutzwiller has published about 40 papers, most of them alone. He received prestigious prizes, such as the Dannie Heinemann prize of the American Physical Society (1993) or the Max-Planck Medal of the German Physical Society (2003). His international recognition is also well documented by four issues of Foundations of Physics (2000/2001), published at the occasion of his 75th birth-day. It is worth mentioning that his research activities were broader than quantum chaos and correlated electrons, they included such diverse topics as dislocations in solids, the quantum Toda lattice and the ephemerides of the moon.

Dionys Baeriswyl, Uni Fribourg

Martin Gutzwiller and his periodic orbits

Michael Berry, H H Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL, UK

In the 1970s, physicists were made aware, largely through the efforts of the late Joseph Ford, that classical hamilto-nian mechanics was enjoying a quiet revolution. The tradi-tional emphasis had been on exactly solvable models, with as many conserved quantities as degrees of freedom, in which the motion was integrable and predictable. Examples are the Kepler ellipses of planetary motion, and the simple pendulum: 'as regular as clockwork'. The new research, incorporating Russian analytical mechanics and computer simulations inspired by statistical mechanics, revealed that most (technically, 'almost all') dynamical systems behave very differently. There are few conserved quantities, and motion, in part or all of the phase space, is nonseparable and unpredictable, that is, unstable: initially neighbouring orbits diverge exponentially. This is classical chaos.It was quickly realised that this classical behaviour must have implications for quantum physics, especially semi-classical physics, e.g. for the arrangement of high-lying

energy levels and the morphology of eigenfunctions. The study of these implications became what is now called quantum chaos (though I prefer the term quantum chaol-ogy). This is an area of research in which Martin Gutzwiller made a seminal contribution, described in the following, which I have adapted from a speech honouring his 70th birthday. Since a substantial part of my own scientific life has been devoted to the development and application to Martin's ideas, I won’t attempt to be detached.

Martin published the last of his series of four papers [1-4] on periodic orbits exactly forty years ago. I encountered them at that time, while Kate Mount and I were writing our review of semiclassical mechanics. That was prehistoric semiclassical mechanics: before catastrophe theory de-mystified caustics, before asymptotics beyond all orders lifted divergent series to new levels of precision, and above all before we knew about classical chaos.

Martin Gutzwiller ca. 1951/52

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Of Martin's series of papers, the most influential was the last one [4], containing the celebrated 'Gutzwiller trace for-mula'. That was a tricky calculation, based on the Van Vleck formula for the semiclassical propagator, giving the density of quantum states (actually the trace of the resolvent op-erator) as a sum over classical periodic orbits. In particular, Martin calculated the contribution from an individual unsta-ble periodic orbit. Nowadays we can see this as one of the 'atomic concepts' of quantum chaology, but in those days chaos was not appreciated. But he emphasized the essen-tial novelty of his calculation in a similar way: it applies even when the classical dynamics is nonseparable. I'm rather proud of what we wrote at the beginning of 1972, as the last sentence of our review:

"Finally, the difficulties raised by Gutzwiller's (1971) theory of quantization, which is perhaps the most exciting recent development in semiclassical mechanics, should be stud-ied deeply in order to provide insight into the properties of quantum states in those systems, previously almost intrac-table, where no separation of variables is possible."

The trace formula could be approximated by taking just one periodic orbit and its repetitions. This led to an approxi-mate 'quantization formula' that gave good results when applied to the lowest states of an electron in a semicon-ductor, whose mass depended on direction. I am referring to the birth of Martin's treatment of the anisotropic Kepler problem [5].

For a few years, his calculation was widely misinterpreted (among the ignorant it is misinterpreted even today) as im-plying a relation between the individual energy levels and individual periodic orbits of chaotic systems. One might call this the 'De Broglie interpretation' of the trace formula: that there is a level at each energy for which the action of a periodic orbit is a multiple of Planck. This is nonsense: the simplest calculation shows that the number of levels is hopelessly overestimated – in a billiard, for example, there is an 'infra-red catastrophe', that is, the prediction of levels at arbitrarily low energies.

Martin's papers quickly inspired others. In 1974, Jacques Chazarain showed that the trace formula could be operated 'in reverse', so that a sum over energy levels generated a function whose singularities were the actions of periodic orbits. This was exact, not semiclassical, and led (often unacknowledged) to what later came to be called 'inverse quantum chaology' and 'quantum recurrence spectrosco-py'. In 1975 Michael Tabor and I generalized some of the results in the first of Martin's semiclassical papers [1] to get the general trace formula for integrable systems, where the periodic orbits are not isolated but fill tori. In nuclear physics, similar formulas had been obtained by Strutinsky in the context of the shell model. Tabor and I used our result to show that the level statistics in integrable systems are Poissonian - more about that later. William Miller and André Voros resolved a puzzle about the application of the trace formula for a stable orbit: by properly quantizing transverse to the orbit, they restored the missing quantum numbers; then Martin's single-orbit quantization rule makes sense, as the 'thin-torus' limit of Bohr-Sommerfeld quantization.

Probably Martin didn't realize that his formula was so fashionable at that time that it induced a certain hysteria. Michael Tabor and I were quietly finishing the work I just

described when we learned that William Miller wanted to visit us in Bristol, to talk about his new work on periodic orbits. We convinced ourselves that this must be the same as ours, and laboured day and night (up a ladder, actually, because Michael was helping me paint my new house) to get our paper written and submitted before he arrived. We were foolish to panic, because William's work was com-pletely different.

An awkward feature of stable orbits, recognized clearly by Martin in those early days, was that focusing occurs along them, leading for certain repetition numbers and stability in-dices to divergences of the contributions he calculated, as-sociated with bifurcations. That awkwardness was removed in 1985 by Alfredo Ozorio de Almeida and John Hannay, who applied ideas from catastrophe theory that had come into semiclassical mechanics in the 1970s. Their develop-ment of Martin's formula became popular much later, when the features they predicted could be detected numerically.

In the early 1970s, Ian Percival made us aware of the amazing developments in classical mechanics by Arnold and Sinai, before chaos became popular. Percival insisted that semiclassical mechanics must take account of chaos. Later, we learned more about chaos from Joseph Ford. Of course Martin had paved the way with his trace formula for unstable orbits.

A persistent question was whether the formula could gen-erate asymptotically high levels for a chaotic system. My opinions fluctuated. In 1976 I thought it could not, arguing that long orbits - required to generate the high levels - were so unstable that the Van Vleck propagator would not be valid for them. Instead, I thought (using ideas developed by Balian and Bloch) that periodic orbits could at best describe spectra smoothed on scales that were large compared with the mean spacing – but still classically small, so that some detail beyond the Weyl rule was accessible, though still not individual levels. This question is still not settled definitively, but my pessimistic opinion was changed by two develop-ments.

The first was energy level statistics. In the 1970s, following a suggestion from Balazs Gyorffy, I imported from nuclear physics the idea that random matrices could be relevant in the quantum mechanics of chaos. The first application of this suggestion was not to chaotic systems at all, but to in-tegrable systems, where it was shown – as I just mentioned – that the levels are not distributed according to random-matrix theory. That work inspired Allan Kaufman and Ste-ven McDonald to the first calculation of level spacings for a chaotic system: the stadium. Then I did the same for Sinai's billiard. In those days we were fixated on the spacings dis-tribution. My way of deriving level repulsion was a generali-zation of Wigner's: through the codimension of degenera-cies. This gave the same result as random-matrix theory for small spacings, and explained the differences between the different ensembles, but gave no clue as to why random-matrix theory worked for all spacings, and why it was con-nected with classical chaos.

Then came Oriol Bohigas and Marie-Joya Giannoni and Charles Schmit. What they did, in the early 1980s, was simple but very important. They repeated the calculations that Kaufman and McDonald and I had done, for the same

36


systems and using the same numerical methods, but in-stead of focusing on the one statistic of the level spacing they appreciated that the random-matrix analogy is much broader: it predicts all the spectral statistics, in particular long-range ones. They calculated one of these: the spectral rigidity (equivalent to the number variance).

Their observation was enormously influential. In particular, it was central to my construction in 1985 of the beginnings of the semiclassical theory of spectral statistics from Mar-tin's atoms: the periodic orbits. Another crucial ingredient in this was also a development of periodic-orbit theory: the in-spired realization by John Hannay and Alfredo Ozorio de Al-meida that the Gutzwiller contributions of long orbits obey a sum rule whose origin is classical and whose structure is universal - that is, independent of details. Pure mathemati-cians (Margulis, Parry, Pollicott) had found similar rules - more general in that they applied to dissipative as well as hamiltonian systems, but also more restricted in that Han-nay and Ozorio's theory applied also to integrable systems (where Tabor and I had found their particular result in 1977 but failed to appreciate its general significance). Thus peri-odic orbits were able to reproduce key formulas from ran-dom-matrix theory, and random-matrix universality found a natural explanation as the inheritance by quantum mechan-ics of the classical universality of long orbits. There was more: the periodic orbit theory of spectral statistics showed clearly and simply why and how random-matrix theory must break down for correlations involving sufficiently many lev-els. There were misty mathematical aspects – now being clarified – of those arguments, but the formulas were not misty, and were the first step in convincing me that long orbits in Martin's trace formula were meaningful.

The second step sprang from the realization - increasingly urgent in the early 1980s - that the series of periodic orbits in the trace formula does not converge. The cause was real-ized by Martin in 1971 [4]:

"Even more serious is the fact that there is usually more than a countable number of orbits in a mechanical system, whereas the bound states of a Hamiltonian are countable."

The failure of the trace formula to converge was empha-sized especially by André Voros, who pointed out that

this defect is shared by the formally exact counterpart of the formula for billiards with constant negative curvature, namely the Selberg trace formula. And later Frank Steiner taught us that trace formulas can sometimes converge con-ditionally, in ways depending delicately on the topology of the orbits (expressed as Maslov phases). Eventually these concerns about convergence led naturally to the study of zeta functions. The idea there is to find a function where the energy levels are zeros, rather than steps or spikes as in the density of states. The grandparent of all these objects is Riemann's zeta function of number theory. I learned its pos-sible relevance to quantum chaology from Oriol Bohigas, and also from Martin's semiclassical interpretation of the Faddeev-Pavlov scattering billiard, where Riemann's zeta function gives the phase shifts [6, 7]. It is amazing that Mar-tin had already realized the connection with zeta functions in his 1971 paper. He wrote:

"This response function is remarkably similar to the so-called zeta functions which mathematicians have invented in order to survey and classify the periodic orbits of abstract mechanical systems."

(He cited Smale). And in 1982 Martin explicitly wrote a semiclassical zeta function of the kind we consider today, and used it in conjunction with some tricks from statistical mechanics to sum the periodic orbits for the anisotropic Kepler system [7, 8].

A crucial ingredient turned out to be the Riemann-Siegel formula, that makes the sum over integers for the Riemann zeta function converge. I realized this in 1986, and later de-veloped the idea with Jon Keating [9]; we were helped by André Voros's precise definitions of the regularized prod-ucts in these zeta functions. The result was an adaptation of the trace formula to give a convergent sum over periodic orbits, soon employed to good effect by Keating and Martin Sieber [10] (see the figure). A related idea was the invention of cycle expansions by Predrag Cvitanovic and Bruno Eck-hardt; in these, essential use is made of symbolic dynam-ics to speed the convergence of the sum over orbits. This application of coding to semiclassical mechanics was also originally Martin's idea: he used it in the 1970s and early 1980s to classify and then estimate the sum over the orbits, again for the anisotropic Kepler problem [7, 8].

The two applications of Martin's periodic-orbit ideas that I have just described, to spectral statistics and to zeta func-tions, were combined by Eugene Bogomolny and Jonathan Keating. This development, and more recent insights from Martin Sieber, Fritz Haake and Sebastian Müller, are tak-ing the derivation of random-matrix formulas from quantum chaology to new levels of sophistication and refinement.

In the mid-1980s, Eric Heller discovered that for some chaotic systems the wavefunctions of individual states are scarred by individual short periodic orbits, in ways that de-pend on how unstable these are. From this came further extensions of Martin's ideas, to new sorts of spectral series of periodic orbits, not involving traces, and for Wigner func-tions as well as wavefunctions.

In spite of all this progress, we are still unable to answer de-finitively and rigorously the central question Martin posed in 1971 [4]:

"What is the relation between the periodic orbits in the clas-

Quantum spectral determinant (zeta function) for a particle con-fined between branches of a hyperbola, calculated exactly (da-shed curve) and from a renormalized version [9,10] of Gutzwiller's sum over the unstable classical periodic orbits (full curve); the energy levels are the zeros, indicated by stars. Reproduced from [10], with permission.

37


sical system and the energy levels of the corresponding quantum system?"

Of course the trace formula itself is one such relation, but I am sure that what Martin meant is: how can periodic orbits be used for effective calculations of individual levels. For the lowest levels there is no problem, but – and again I quote from Martin’s 1971 paper -

"the semiclassical approach to quantum mechanics is sup-posed to be better the larger the quantum number"

and to reproduce the spectrum for high levels, using even the convergent versions of the trace formula that are now available, requires an exponentially large number of peri-odic orbits. This is a gross degree of redundancy unaccept-able to anybody who appreciates the spectacular power of asymptotics elsewhere. Martin's old ideas continue to challenge us.

A few years ago, I refereed an application for research fund-ing for a German-British collaboration. This required me to comment on the applicants' "timetable for research" and their "list of deliverables". I wrote "In science there are no deliverables; researches are not potatoes". Martin Gutzwill-er ignored these toxic fashions. What makes him so attrac-tive as a scientist is that he refuses to follow any fashion; instead, he generates ideas that become the fashion.

References[1] Gutzwiller, M. C.,1967, The Phase Integral Approximation in Momentum Space and the Bound States of an Atom J. Math. Phys. 8, 1979-2000[2] Gutzwiller, M. C.,1969, The Phase Integral Approximation in Momentum Space and the Bound States of an Atom II J. Math. Phys. 10, 1004-1020[3] Gutzwiller, M. C.,1970, The Energy Spectrum According to Classical Mechanics J. Math. Phys. 11, 1791-1806[4] Gutzwiller, M. C.,1971, Periodic orbits and classical quantiza-tion conditions J. Math. Phys. 12, 343-358[5] Gutzwiller, M. C.,1973, The Anistropic Kepler Problem in Two Dimensions J. Math. Phys. 14, 139-152[6] Gutzwiller, M. C.,1983, Stochastic behavior in quantum scat-tering Physica D 7, 341-355

[7] Gutzwiller, M. C.,1982, The Quantization of a Classically Er-godic System Physica D 5, 183-207[8] Gutzwiller, M. C.,1977, Bernoulli Sequences and Trajectories in the Anisotropic Kepler Problem J. Math. Phys. 18, 806-823[9] Berry, M. V. & Keating, J. P.,1992, A new approximation for zeta(1/2 +it) and quantum spectral determinants Proc. Roy. Soc. Lond. A437, 151-173[10] Keating, J. P. & Sieber, M.,1994, Calculation of spectral deter-minants Proc. Roy. Soc. Lond. A447, 413-437

Martin Gutzwiller and his wave function

Dionys Baeriswyl, Département de physique, Université de Fribourg, 1700 FribourgWerner Weber, Fakultät Physik, Universität Dortmund, DE-44221 Dortmund

Gutzwiller's work on correlated electrons is mostly con-centrated in three papers, written in the time span 1962 to 1964 [1, 2, 3]. A short fourth paper was published a few years later [4]. In essence, Gutzwiller introduced a variation-al ansatz, where charge fluctuations are reduced as com-pared to Hartree-Fock theory, thus quantifying Van Vleck's qualitative idea of minimum polarity [5].

Historically, electronic correlations were first studied for the homogeneous electron gas, much less for electrons in nar-row bands such as d-electrons in transition metals. A no-ticeable exception was Anderson's paper on the kinetic ori-gin of antiferromagnetism in transition metal compounds, where a localized basis of Wannier functions was used [6]. In the same spirit, Gutzwiller wrote down the Hamiltonian

( ) ( )H t c c c c U n n 1,

ii j

j j i i ii

=- + + - .@ @v v v v/ /

where the first term describes electron hopping between the neighboring sites of a lattice (ci

@v and civ are, respec-

tively, creation and annihilation operators for electrons at site i with spin s) and the second term is the interaction, which acts only if two electrons meet on the same site (n c ci i i= @

v v v ). Quantum chemists had previously used a similar model for p-electrons in conjugated polymers, but they had included the long-range part of the Coulomb inter-action. Curiously, shortly after Gutzwiller's first paper on the subject, two publications appeared where the same Ham-iltonian (1) is treated, but without reference to Gutzwiller's work, one by Hubbard [7], the other by Kanamori [8]. One

After graduating from Exeter and St Andrews, Michael Berry entered Bristol University, where he has been for consid-erably longer than he has not. He is a physicist, fo-cusing on the physics of the mathematics…of the physics. Applications in-clude the geometry of singularities (caustics on large scales, vortices on fine scales) in optics and other waves, the connec-tion between classical and quantum physics, and the physical asymptotics of divergent series. He delights in finding the arcane in the mundane – abstract and subtle concepts in familiar or dramatic phenomena:- Singularities of smooth gradient maps in rainbows

and tsunamis;- The Laplace operator in oriental magic mirrors;- Elliptic integrals in the polarization pattern of the

clear blue sky;- Geometry of twists and turns in quantum indistin-

guishability;- Matrix degeneracies in overhead-projector trans-

parencies;- Gauss sums in the light beyond a humble diffraction

grating.

38


has to conclude that the three papers [1, 7, 8] were written completely independently and that the Hamiltonien (1), now universally referred to as Hubbard model, was in the air, especially for investigating the problem of correlated elec-trons in transition metals.

In contrast to Gutzwiller, who did not care too much about the justification of the model, Hubbard estimated the dif-ferent Coulomb matrix elements between localized d wave functions, and he also explained how in transition metals with partly filled 3d shells and a partly filled 4s shell the s-electrons can effectively screen the Coulomb interactions between d-electrons. The fact, pointed out by Gutzwiller [3], that the three authors, himself, Hubbard and Kanamori, obtained qualitatively different results, shows that, despiteof its formal simplicity, the model was – and still is – very challenging.

Gutzwiller's main contributions to the field of correlated electrons are his ansatz for the ground state of the Hubbard model and his ingenious way of handling this wave function. He starts from the ground state 0W of the hopping term, the filled Fermi sea. This would just yield the Hartree-Fock approximation, which treats neutral and "polar" configura-tions on the same footing. Thus he adds a projector term, now called correlator, that reduces charge fluctuations. His ansatz reads

( )n n1 1 2i ii

0hW W= - - - .^ h6 @%

or, written in a different way,

( )e 3gD0W W= - t

where D n ni ii

= - .t / is the number of doubly occupied sites

and g is related to Gutzwiller’s parameter by = e-g.

The problem of evaluating the ground state energy

( )EH

4WW WW W

=t

6 @

for this trial state still represents a formidable task. Exact results were only obtained in one dimension [9, 10]. For oth-er dimensions, Variational Monte Carlo (VMC), pioneered for the Gutzwiller ansatz by Horsch and Kaplan [11], has been widely used in recent years [12].

Gutzwiller himself proposed an approximate way of evalu-ating Eq. (4) [3]. His procedure, known as "Gutzwiller ap-proximation", involves two steps [13]. In a first step, the expectation value is factorized with respect to spin. In a second step, the remaining expectation values are as-sumed to be configuration-independent. This leads to a purely combinatorial problem. In the limit of infinite dimen-sions, the Gutzwiller approximation represents the exact solution for the Gutzwiller ansatz, as shown by Metzner and Vollhardt [14, 10]. This interesting result marked the begin-ning of a new era in the theory of correlated electrons, that of the Dynamical Mean-Field Theory [15].

The result of the Gutzwiller approximation can be represent-ed in terms of a renormalized hopping, t " gt. For U " ∞,

g depends on the electron density n as g = (1 - n)/(1 - n/2). Therefore, when approaching half filling (n " 1), the elec-tron motion is completely suppressed, and the system is a Mott insulator. Brinkman and Rice noticed that within the Gutzwiller approximation the jamming of electrons (for n = 1) occurs at a large but finite value of U and is signaled by the vanishing of double occupancy [16]. They associated the critical point with the Mott metal-insulator transition. However, a closer scrutiny shows that this conclusion is an artifact of the Gutzwiller approximation. Indeed, for an exact treatment of the Gutzwiller ansatz (and finite lattice dimensions) double occupancy remains finite for all finite values of U. Moreover, the Gutzwiller ansatz itself is of lim-ited validity for large values of U, as seen clearly by com-paring it with the exact solution in one dimension.

Nevertheless, a Mott transition does occur for the Hubbard model, but in the sense of a topological transition from a phase with finite Drude weight for small values of U to one with vanishing Drude weight at large U, in agreement with Kohn’s distinction between metals and insulators [17]. To show this in a variational framework 1, we have used a pair of trial ground states [18], the Gutzwiller wave function W together with the "inverted" ansatz

( )e 5hTW W= 3-lt

where ( )T c c c c,

ii j

j j j= +@ @v v v v

t / is the hopping operator, W3

is the ground state for U " ∞ and h is a variational param-

eter. One readily shows that W has a finite Drude weight and lower energy for small U, while the Drude weight van-ishes for Wl , which is preferred for large U. A metal-insu-lator transition occurs for a value of U of the order of the band width, in good agreement with Quantum Monte Carlo results.

So far, we have assumed the Gutzwiller ansatz to be "adi-abatically" linked to the filled Fermi sea 0W , which is the main reason for the metallic character of W . However, if we allow for a broken symmetry within 0W , we may find a competing ground state with qualitatively different proper-ties. For instance, allowing for different magnetic moments on the two sublattices of a bi-partite lattice, one can obtain an antiferromagnetic insulator already below the Mott tran-sition, i.e., before electrons are essentially localized. This is indeed found for the square lattice (n = 1), where the Mott transition is replaced by a smooth crossover from a band (or "Slater" [19]) insulator with small alternating magnetic moments at small U to a (Heisenberg) antiferromagnetic insulator with fully developed local moments at large U. Interestingly, this is not the case for the honeycomb lat-tice, where antiferromagnetism sets in essentially together with the Mott transition [20], although the detailed behavior close to the transition appears to be more complicated – and quite intriguing [21].

As a second example of a broken symmetry we mention bond alternation in conjugated polymers, or, more precise-ly, the fate of the Peierls instability in the presence of Cou-lomb interaction. Eric Jeckelmann, during his Ph.D. thesis,

1 From this point on, we will concentrate mostly on our own work, with apologies to other authors.

39


studied the one-dimensional Peierls-Hubbard model where the bond length dependence of the hopping amplitude t provides a coupling between the electrons and the lattice [22]. He used the Gutzwiller ansatz but added both the electronic gap and the lattice dimerization as variational parameters. The result for the dimerization D, as a function of U and for fixed electron-lattice couplings , is shown in Fig. 1. In contrast to Unrestricted Hartree-Fock, where the Peierls insulator is rapidly replaced by a spin-density wave (a Slater insulator), the dimerization is found to remain finite for all values of U. It even increases initially, as discovered long before this work [23], and exhibits a maximum for U ≈ 4t, where a crossover to spin-Peierls behavior occurs. These variational results are in good agreement with sub-sequent calculations using the Density Matrix Renormaliza-tion Group.

As a third example we discuss results of the Ph. D. thesis of David Eichenberger [24], who studied the Hubbard model on a square lattice, using the modified Gutzwiller ansatz

( )e e 6hT gD0W W= - -t t

The additional factor e hT- t leads to a substantial improve-ment of the ground state energy and provides a kinetic ex-change. We were particularly interested in the possibility of a superconducting ground state with d-wave symmetry, taken into account in the reference state 0W . Fig. 2 shows the VMC result for the superconducting order parameter for the Hubbard model on an 8×8 square lattice with both nearest (t) and next-nearest neighbor hoppings (t') and a realistic Hubbard parameter U = 8t. Our results agree very well with other studies using completely different methods.

We turn now to the problem of itinerant ferromagnetism, which has been the main motivation for Gutzwiller (and for Hubbard and Kanamori as well) to study the Hamilto-nian (1). The most simple trial state is the ground state of an effective single-particle model where the bands for up and down spins are shifted relative to each other. The "ex-change splitting" is then determined by minimizing the to-tal energy. This leads to the Stoner criterion, according to

which ferromagnetism occurs if U(eF) > 1, where (eF) is the density of states per spin at the Fermi energy. Already in 1953 Van Vleck argued that the Stoner theory could not be the whole story, but that electronic correlations had to be taken into account. Gutzwiller’s scheme is well suited for doing that. The results obtained in this way still leave space for ferromagnetism, but the stability region in parameter space is strongly reduced as compared to that of Stoner’s theory [25]. In fact, the necessary U values are so large that one has to conclude that the single-orbital Hubbard model is not adequate for describing the ferromagnetism of transi-tion metals.

There is another more fundamental reason why the single-band Hubbard model cannot be taken too seriously for describing transition metals. These materials are charac-terized by narrow partly filled 3d-bands located within a broad s-band and overlapping with even broader p bands, and therefore it is far from obvious how a one-band model should be able to describe their magnetic properties. This problem must have been clear to Gutzwiller, who used the smart title "Correlation of Electrons in a Narrow s Band" for one of his papers [3]. Notwithstanding this loophole, a real-istic model should add uncorrelated electrons representing the s-band to the correlated electrons of the d-band. The Periodic Anderson Model is a first step in this direction, it admits two orbitals at each site, one of which is localized and correlated through an on-site interaction, the other is delocalized and uncorrelated. The two bands are hybrid-ized. Using a generalized Gutzwiller ansatz together with a corresponding Gutzwiller approximation, one finds not only the usual renormalization of the correlated band by a factor g, but also a renormalization of the hybridization by √g [26, 27].

The next step is to treat two or more correlated orbitals at a site. Here, Jörg Bünemann in his Ph.D. thesis has con-tributed a great deal to generalize the Gutzwiller formalism [28]. The generalization leads to an enormous expansion of the Gutzwiller wave function, as many additional correla-tors have to be introduced. The relevant local multi-electron configurations can be represented by the eigenstates of an atomic Hamiltonian, which reproduces the atomic multiplet spectrum of the partly filled 3d shell. This extension also

Figure 1: Dimerization in the Hubbard-Peierls model. Circles: VMC, full lines: analytical small U expansion, broken lines: Unre-stricted Hartree-Fock.

0.20

0.15

0.10

0.05

0.00

Δ /(

2t)

86420

U / t

λ = 0.2

λ = 0.1

Figure 2: Superconducting order parameter as a function of do-ping for the Hubbard model on the square lattice.

40


leads to a rapid increase of the number of variational pa-rameters in the Gutzwiller wave function. If the number of different orbitals is N (N can be as large as 5 for an open d shell), the number of independent variational parameters can reach 22N - 2N - 1, which may be of the order of 1000 [28]. The variational parameters represent the occupan-cies of all possible multiplet states. At the first instance, the atomic multiplet spectrum is governed by three Slater-Condon or Racah integrals, when spherical symmetry is as-sumed for the atoms. Yet, the site symmetry in a crystal is lower than spherical. Incorporation of the correct site sym-metry results in many further modifications and extensions of the method.

The multi-band Gutzwiller method allows the investigation of 3d transition metals and compounds on a quantitative basis. An ab initio single-particle Hamiltonian can be con-structed using Density-Functional Theory (DFT). The sim-plest way to incorporate DFT results is to extract a tight-binding model by fitting the hopping amplitudes to the DFT bands, but more elaborate methods are available, such as down-folding the DFT bands to a reduced Wannier basis [29]. We have carried out various studies on magnetic 3d elements and on compounds of 3d elements. One paper dealt with the Fermi surface of ferromagnetic Ni. DFT pre-dicts a hole ellipsoid around the X point of the Brillouin zone, which is missing in the data. The multi-band Gutzwill-er method was based on a one-particle Hamiltonian de-rived from paramagnetic DFT bands for Ni including wide 4s and 4p bands.Using typical interaction parameters for Ni, our calcula-tions reproduced the observed Fermi surface topology [30]. Another paper dealt with the magnetic anisotropy in ferro-magnetic Ni [31]. Here again, pure DFT results did not yield the correct answers, while the Gutzwiller method gave very good agreement with experiment. In all cases, the renor-malization parameters g have been found to be of the order of 0.7, indicating moderately strong correlation effects.

Finally we mention the issue of metallic anti-ferromagnetism in iron pnictides, a new class of high-temperature super-conductors. Our calculations were based on down-folded DFT bands. The results indicate also in this case moderate-ly strong correlations. The atomic magnetic moments were found to agree well with experiment, in contrast to the DFT results and also to model calculations [32].

The examples mentioned above demonstrate that Gutzwill-er's simple ansatz evolved into a powerful tool for dealing with correlated electron systems. The method has recently also been applied successfully to cold bosonic atoms in an optical lattice. At the age of 50, Gutzwiller’s wave function in its extensions remains competitive for describing corre-lated states of matter.

References[1] M. C. Gutzwiller, Phys. Rev. Lett. 10, 169 (1963).[2] M. C. Gutzwiller, Phys. Rev. 134, A923 (1964).[3] M. C. Gutzwiller, Phys. Rev. 137, A1726 (1965).[4] K. A. Chao and M. C. Gutzwiller, J. Appl. Phys. 42, 1420 (1971).[5] J. H. van Vleck, Rev. Mod. Phys. 25, 220 (1953).

[6] P. W. Anderson, Phys. Rev. 115, 2 (1959).[7] J. Hubbard, Proc. Roy. Soc. A276, 238 (1963).[8] J. Kanamori, Prog. Theor. Phys. 30, 275 (1963).[9] W. Metzner and D. Vollhardt, Phys. Rev. Lett. 59, 121 (1987); F. Gebhard and D. Vollhardt, Phys. Rev. Lett. 59, 1472 (1987).[10] For a review see F. Gebhard, The Mott Metal-Insulator Transi-tion: Models and Methods, Springer 1997.[11] P. Horsch and T. A. Kaplan, J. Phys. C 16, L1203 (1983).[12] For a recent review of the method for the fully projected Gutz-willer wave function (g " ∞) see B. Edegger, V. N. Muthukumar and C. Gros, Adv. Phys. 56, 927 (2007).[13] For a clear presentation see P. Fulde, Electron Correlations in Molecules and Solids, Springer Series in Solid-State Sciences 100 (1990).[14] W. Metzner and D. Vollhardt, Phys. Rev. Lett. 62, 324 (1989).[15] For an early review see A. Georges, G. Kotliar, W. Krauth and M. J. Rozenberg, Rev. Mod. Phys. 68, 13 (1996).[16] W. Brinkman and T. M. Rice, Phys. Rev. B 2, 4302 (1970).[17] W. Kohn, Phys. Rev. 133, A171 (1964).[18] L. M. Martelo, M. Dzierzawa and D. Baeriswyl, Z. Phys. B 103, 335 (1997).[19] J. C. Slater, Phys. Rev. 82, 538 (1951).[20] M. Dzierzawa, D. Baeriswyl and L. M. Martelo, Helv. Phys. Acta 70, 124 (1997); for a review see D. Baeriswyl, Found. Phys. 30, 2033 (2000).[21] Z. Y. Meng, T. C. Lang, S. Wessel, F. F. Assaad and A. Mura-matsu, Nature 464, 847 (2010).[22] E. Jeckelmann, Ph D. thesis, University of Fribourg (1995); E. Jeckelmann and D. Baeriswyl, Synth. Met. 65, 211 (1994).[23] P. Horsch, Phys. Rev. B 24, 7351 (1981); D. Baeriswyl and K. Maki, Phys. Rev. B 31, 6633 (1985).[24] D. Eichenberger, Ph. D. thesis, University of Fribourg (2008); D. Baeriswyl, D. Eichenberger and M. Menteshashvili, New J. Phys. 11, 075010 (2009).[25] P. Fazekas, Electron Correlation and Magnetism, World Sci-entific 1999.[26] T. M. Rice and K. Ueda, Phys. Rev. Lett. 55, 995 (1985).[27] C. M. Varma, W. Weber and L. J. Randall, Phys. Rev. B 33, 1015 (1986).[28] J. Bünemann, Ph. D. thesis, University of Dortmund (1998); J. Bünemann, W. Weber and F. Gebhard, Phys. Rev. B 57, 6896 (1998).[29] For a recent review see O. K. Andersen and L. Boeri, Ann. Phys. (Berlin) 523, 8 (2011).[30] J. Bünemann et al., Europhys. Lett. 61, 667 (2003).[31] J. Bünemann, F. Gebhard, T. Ohm, S. Weiser and W. Weber, Phys. Rev. Lett. 101, 236404 (2008).[32] T. Schickling et al., Phys. Rev. Lett. 108, 036406 (2012).

Werner Weber received his PhD from the TU Munich in 1972. He worked first at a variety of research institu-tions, at the MPI for Solid State Research in Stuttgart, at the Research Center in Karlsruhe (now K.I.T.), at Bell Laboratories, Murray Hill. He then became a fac-ulty member at the TU Dortmund, where he retired in 2010. His research area is theoretical solid state phys-ics, with main emphasis on materials science theory. He assumed many duties in university self-administra-tion, even presently. In the spirit of Martin Gutzwiller, he recently changed his field of interest to activities in climate research, including applications.

41


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"Lead-User-Workshops" für effizientesInnovations- & Produktvariantenmanagement

Bernhard Braunecker und Richard Wenk

Industriephysiker in ManagementfunktionPhysiker sind in der Industrie nicht nur in Forschung und Entwicklung tätig, sondern auch als Produktmanager. In dieser Funktion müssen sie sich um drei Fragen kümmern: a) wie leistungsstark und erprobt sind die dem Produkt und dem Herstellprozess zugrunde liegenden Technologien, b) wie gut deckt das Produkt heutige und zukünftige Kun-denanwendungen ab und c) wie wird es sich am Markt be-haupten? Um den wirtschaftlichen Erfolg des Produkts zu sichern, müssen alle drei Fragen kohärent, also im Kontext positiv beantwortet sein. Die Abhängigkeit der Fragestel-lungen voneinander spiegelt sich zum Beispiel bei der Fest-legung des Produktkonzepts wider: einerseits möchte man ein entsprechend grosses Angebot an Produktvarianten, um ein möglichst breites Kundenspektrum abzudecken; anderseits erfordern die für den Markterfolg zu minimie-renden Herstell- und Vertriebskosten die Beschränkung auf nur wenige Varianten. Selbst wenn man den Widerspruch dadurch löst, dass man die Produkte baukastenmässig aus Modulen aufbaut, bleibt dennoch die Frage b) zu beantwor-ten, ob sich damit auch alle gewünschten Kundenapplika-tionen erfüllen lassen?

Man sieht, dass die drei Fragestellungen ein profundes Verständnis der technisch-kommerziellen Abhängigkeiten erfordern, besonders, wenn neue Technologien ins Spiel gelangen. Während die Marktaspekte von Marketingleuten abgedeckt werden können, muss die Schnittstelle der Ap-plikationen gemeinsam von Marketing und F&E bearbeitet werden. Sollte sich das angesprochene Modularkonzept dann als geeignet und machbar erweisen, ist es Aufgabe der F&E - Wissenschaftler, die Funktionalität und die Struk-tur der Module festzulegen. Nur wie lässt sich in diesem iterativen und mit vielen Fragezeichen versehenen Prozess mehr Gewissheit über das richtige Vorgehen gewinnen?

Ein sehr leistungsstarkes Werkzeug dazu sind sogenannte Lead-User-Workshops, wo man als Produkthersteller mit Repräsentanten wichtiger Kunden gemeinsam herauszufin-den versucht, welche neuen Anwendungen durch den Ein-satz kommender Technologien denkbar wären, und welche Produktvarianten dazu infrage kämen? Der Meinungsaus-tausch geschieht im gegenseitigen Interesse, da danach beide Seiten die Folgen anstehender Entscheide besser einzuschätzen vermögen. Bevor im Folgenden auf die Ge-staltung eines solchen Workshops eingegangen wird, sei am Beispiel der Optikindustrie illustriert, dass Veranstal-tungen dieser Art zur Bildung von auch in Krisensituationen belastbaren Interessengemeinschaften (Communities) füh-ren können.

Alpha-Beziehungen von Physikern zwischen FirmenUnter diesem Begriff sei verstanden, wenn die Geschäfts-beziehung zweier Firmen über das übliche Kunden/Lie-ferantenverhältnis hinausgeht, wenn also beider Primär-interessen strategisch in die gleiche Richtung zielen. Als klassisches Beispiel gilt das in der Optikindustrie enge Verhältnis zu den Glasherstellern, deren beste Lieferqua-lität gerade gut genug ist für hochwertige Optiksysteme. Besonders wichtig war und ist der Kontakt zwischen den Optikentwicklern im deutschsprachigen Raum und den Glasexperten von Schott in Mainz, um die hohen Qualitäts-ansprüche ans Glas, aber auch die Komplexität der Glas-produktion jeweils der anderen Seite verständlich zu ma-chen. Dazu organisiert Schott seit Jahrzehnten regelmässig sogenannte "Designer"-Treffen, zu denen die gesamte Op-tikindustrie ihre Wissenschaftler schickt, um Probleme und Anregungen zu artikulieren.

Als Folge dieser Treffen bildete sich unter den Optikent-wicklern eine Gemeinschaft über Firmengrenzen hinaus und bei vielen Kollegen zusätzlich auch ein enges Verhält-nis zu den Glasproduktionsleuten, das sich zur Lösung von Problemfällen in der täglichen Praxis als vorteilhaft erweist. Als vor einigen Jahren japanische Glasherstellern über-raschend "bleifreie" Gläser am Markt lancierten, konnte Schott unter Mithilfe der Experten aller grosser Optikfirmen im deutschsprachigen Raum rasch und gezielt auf die neue Situation reagieren. Diese "Alpha-Beziehungen" sind daher für beide Seiten ein wirksames Mittel der Risikominimie-rung (risk mitigation), sowohl in technischen Belangen, wie in der strategischen Ausrichtung.

Konzept eines "Lead-User-Workshops"Im Folgenden wird die Vorgehensweise beschrieben, wie vor einigen Jahren bei Leica Geosystems in Heerbrugg ein Lead-User-Workshop zum anstehenden Thema der Digita-lisierung von Vermessungsgeräten organisiert wurde. Dazu wurden 15 Experten aus aller Welt aus den Bereichen der amtlichen Landesvermessung, der Industrie, dem Bauwe-sen und der Denkmalpflege (cultural heritage) eingeladen. Das Ziel war, internes Technologie-Knowhow mit dem Ap-plikations-Knowhow der externen Experten zu kombinie-ren. Im Vorfeld des WS wurden verschiedene, für Leica in-teressante Applikationsfelder (total 6) definiert, die dann am WS vorgestellt und bearbeitet werden sollten. Dabei sollten die externen Experten nach Kenntnis der neuen Techno-logieansätze sich nicht nur mit den möglichen Folgen für ihr eigenes Arbeitsgebiet auseinandersetzen, sondern auch mit dem ihrer Kollegen. Das sollte wichtige Argumente für die erwähnte Modularisierung liefern.

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Auswahl der externen TeilnehmerDie Auswahl der Experten ist die wichtigste Aufgabe, die von den Marketing- und Vertriebsleuten, gemeinsam mit den Auslandsvertretern, vorgenommen werden muss. Als Kriterien gelten, dass zu den Personen ein langjähriges Vertrauensverhältnis besteht, dass sie als Entscheidungs-träger mit technischem Hintergrund noch Kenntnis der Ab-läufe in der täglichen Praxis haben, und dass sie offen für Neues sind.

• In unserem Falle waren die Experten in folgenden Orga-nisationen tätig:

a) Fünf Ingenieurbüros und KMUs mit Fokus auf Archi-tektur, Katastervermessung, Hoch-/Tiefbau, Tunnelbau, b) fünf Institutionen (Universitäten, Behörden, Ämter für Denkmalpflege), und c) fünf "Big players" (Shell Oil, Bri-tish Rail, CERN & US-Freeway companies).

• Sie kamen aus vier Regionen, logarithmisch gewichtet:

a) Schweiz, b) Deutschland / Österreich, c) Europa, d) USA,

• Und sie deckten folgende Applikationsfelder ab: a) Traditionelle Märkte, b) Nischenmärkte mit Wachs-

tumspotential, c) Neue Märkte.

GruppeneinteilungEs wurden drei Arbeitsgruppen mit jeweils fünf externen Experten gebildet, wobei in jeder Gruppe alle vier Regi-onen vertreten waren. Jeder Gruppe wird zugeteilt ein Mo-derator, sowie ein Produktmanager aus Marketing und ein technischer Berater aus F&E, die nur bei Klärungsbedarf eingreifen sollten.

Ablauf der VeranstaltungDie Teilnehmer in den 3 Gruppen mussten jeweils zwei der Applikationsfelder wie folgt bearbeiten:Schritt 1: Erarbeiten von speziellen Messabläufen (User Workflow) in den definierten Applikationsfeldern.Schritt 2: Identifizieren von Problemen und deren Lösung, um den Messablauf wesentlich zu vereinfachen und zu ver-kürzen.Schritt 3: Identifizieren von Kundenanforderungen für zu-künftige Messsysteme.Schritt 4: Erarbeiten von Konzeptvorschlägen für zukünf-tige Messsysteme.

Der Workshop (Figur 1) wurde dreiteilig angelegt:• Im Teil 1 schilderte jeder Teilnehmer typische Abläufe

seiner täglichen Arbeit und verwies auf Probleme und Verbesserungswünsche (Schritte 1 & 2). Damit gewann jedes Gruppenmitglied Kenntnis über die Tätigkeiten der Anderen. Nach der Gruppenarbeit präsentierte der Moderator im Plenum vor allen Teilnehmern erste Ge-meinsamkeiten in der noch sehr heterogenen Analyse und skizzierte erste Verbesserungswünsche.

• Im Teil 2 informierte der F&E-Leiter der einladenden Firma, welche neuen Technologien in nächster Zeit zu erwarten sind. Dieser Schritt ist der psychologisch wich-tige Icebreaker, der im geschilderten Fall auch zu einer spürbaren Solidarisierung der Experten untereinander und mit dem Veranstalter führte.

• Im Teil 3 wurden in neuer Zusammensetzung der Grup-pen die Konzeptvorschläge für zukünftige Messsysteme (Schritte 3 & 4) diskutiert, nun allerdings im Wissen kom-mender Technologiemöglichkeiten. Da die Grundaufga-ben aller Teilnehmer meist ähnlicher Natur waren, war die Diskussion in allen Gruppen deutlich einheitlicher als am ersten Tag. Die darauf vorbereiteten Moderatoren lenkten deshalb die Diskussion in Richtung allgemein einsetzbarer Hardware- und Softwaremodule. Nach erneuter Präsentation der Gruppenarbeiten im Plenum gab der Vertreter des Veranstalters dann eine erste Zu-sammenfassung der Erkenntnisse (Wrap up).

Ergebnis, Auswertung, weitere SchritteNach Ablauf des WS wurden die gesammelten Kunden-anregungen für verschiedene Applikationen in den pre-definierten Anwendungsfeldern in drei Bereiche unterteilt: generelle Anwender-, Technologie- und Produktanforde-rungen. In jedem Bereich wurden die Empfehlungen dann konsolidiert, also möglichst vereinheitlicht über alle Anwen-Figur 1: Teilnehmer eines Lead User Workshops

bei Leica Geosystems

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dungsfelder hinweg. So konnte man bei den generellen An-wenderanforderungen vier Untergruppen bilden, für Genau-igkeitssteigerungen, höhere Effizienz des Messsystems, geringere Störanfälligkeit und mehr Bedienerfreundlichkeit; im Bereich der Technologie gab es neun Untergruppen wie Empfehlungen für Echtzeit-Systeme und vereinheitlichtes Datenformat und im Bereich der Produktanforderungen sieben Untergruppen, wie z.B. für handhaltbare statt stativ-montierte Instrumente, Multisensor Systeme, etc.

Aus diesen Anforderungskatalogen wurden dann Funk-tionen für die verschiedenen Produktgruppen abgeleitet. Grundsätzlich wurde dabei unterschieden zwischen Pro-duktverbesserungen, also Optionen für die unmittelbare Zukunft, Innovationen, die interne F&E Anstrengungen benötigen, und Visionen, also Konzepte für zukünftige Sy-steme, die eine Grundlagenentwicklung mit Hochschul-partnern bedingen. Daraus wurden dann konkrete Produkt-ideen abgeleitet, woraus letztendlich für die verschiedenen Produktkategorien 17 Produktvorschläge resultierten.

Diese Produktideen flossen dann bei den entsprechenden Divisionen in deren Roadmap-Prozess ein, wurden von den Produkt- und Technologiespezialisten dort hinter-fragt, und es wurden realistische Produktentwicklungen definiert. Einige dieser Ideen konnten noch in bereits lau-fende Produktentwicklungen eingebracht werden, ande-re wurden verworfen aus Gründen der Machbarkeit oder weil der Bedarf aus Kundensicht noch nicht gegeben war, wieder andere wurden zurückgestellt, beziehungsweise als Kandidaten für externe Entwicklungen mit Hochschulen vorgesehen. Dabei wurde verstärktes Augenwerk auf eine mögliche Modularisierung gerichtet, also auf die Mehrfach-verwendung von Grundmodulen (Principal Components) in verschiedenen Instrumenten und Dienstleistungen.

Optimales Konzept des VariantenmanagementsDie gewonnenen Erkenntnisse aus einem Lead-User-Work-shop fliessen in die Auslegung zukünftiger Instrumente ein.

Wie einleitend angedeutet, soll ein breites Angebot an Pro-duktvarianten möglichst viele Kundenapplikationen abde-cken, demzufolge sich aus Logistik- und Kostengründen ein modular hierarchischer Aufbau (Figur 2) empfiehlt: Teure Basismodule wie Optik, Mechanik und Elektronik werden standardisiert, also konstruktiv vereinheitlicht, während die Produktdifferenzierung möglichst weit ans Ende der Wert-schöpfungskette geschoben wird, im Idealfall sogar in rei-ne Softwaremodule. Im Gegensatz zu früher kann deshalb auch die kostengünstigste Variante die beste Hardware enthalten, wenn es sich wegen der grösseren Stückzahl und der Fertigungsautomatisierung lohnt. Die eigentliche Kernfrage lautet deshalb, mittels welcher Modulfunktionen kann Redundanz reduziert und die angestrebte Vollständig-keit des Applikationsspektrum realisiert werden? Bei der Beantwortung dieser Frage helfen die wichtigen Erkennt-nisse aus dem Lead User Workshop.

Figur 2: Produktvarianten P1…P5: Die Hardwareplattformen Optik & Mechanik sind konzeptionell zu vereinheitlichen und an einem Standort vollautomatisch herzustellen. Der Einbau der "intermedi-ate" Module von Elektronik & Sensorik kann weltweit an mehreren Standorten durchgeführt werden, während die applikationsspezi-fischen Software-Module im Idealfall vom Kunden selber freige-

schaltet werden können.

Richard Wenk ist CTO und Vizepräsident bei Hexagon Geosystems, zu der auch Leica Geosystems in Heer-brugg gehört.

History of Physics (4)

From Static to Expanding Models of the Universe

Norbert Straumann, Uni Zürich

At the end of some historical remarks in the article on the 2011 Nobel Prize [1], it was announced that the author would indicate in a historical essay the interesting early his-tory of cosmology. One of the reasons is that this is not even well-known among cosmologists, and is often distort-ed. In the words of the late Allen Sandage: "In 1929, Edwin Hubble published a paper that correlated redshifts of galax-ies with distances he had estimated from calibration of their absolute magnitudes previously made in 1926. Writers of both popular accounts and technical textbooks have often described this as the discovery of the expanding universe. This is not so." [2]

Einstein's static model of the universe

On 8 February 1917, in the middle of the most terrible time during the First World War, Einstein gave a talk in the Preus-sian Academy of Sciences on an application of his general relativity on the universe as a whole. One week before the German military leadership had declared in the same city the unconstrained submarine war. Einstein’s first paper on cosmology [3] marks in many ways the beginning of mod-ern cosmology.Perhaps the main reason why Einstein turned so soon af-ter the completion of general relativity to cosmology had much to do with Machian ideas on the origin of inertia,

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which played in those years an important role in Einstein’s thinking. His intention was to eliminate all vestiges of ab-solute space. He was, in particular, convinced that isolated masses cannot impose a structure on space at infinity. Ein-stein was actually thinking about the problem regarding the choice of boundary conditions at infinity already in spring 1916. In a letter to Michele Besso from 14 May 1916 he also mentions the possibility of the world being finite. A few months later he expanded on this in letters to Willem de Sitter. It is along these lines that he postulated a Universe that is spatially finite and closed, a Universe in which no boundary conditions are needed 1. He then believed that this was the only way to satisfy what he later [5] named Mach’s principle, in the sense that the metric field should be determined uniquely by the energy-momentum tensor.In addition, Einstein assumed that the Universe was static. This was not unreasonable at the time, because the rela-

tive velocities of the stars as observed were small. (Re-call that astronomers only learned later that spiral neb-ulae are independent star systems outside the Milky Way. This was definitely established when in 1924 Hubble found that there were Cepheid variables in Andromeda and also in oth-er nearby galaxies. Einstein compares the observed small peculiar velocities of stars with the speed of light.)These two assumptions

were, however, not compatible with Einstein’s original field equations. For this reason, Einstein added the famous L-term, which is compatible with the principles of general relativity. The cosmological term is, in four dimensions, the only possible complication of the field equations if no high-er than second order derivatives of the metric are allowed (Lovelock theorem). This remarkable uniqueness is one of the most attractive features of general relativity. (In higher dimensions additional terms satisfying this requirement are allowed.)For the static Einstein universe the field equations with the cosmological term imply the two relations

Ga

4 12r t K= = ,

where is the mass density of the dust filled universe (zero pressure) and a is the radius of curvature. For L = 0 the density would have to vanish. (We remark, in passing, that the Einstein universe is the only static dust solution; one does not have to assume isotropy or homogeneity.) Ein-stein was very pleased by this direct connection between the mass density and geometry, because he thought that this was in accord with Mach's philosophy.Einstein concludes with the following sentences:

"In order to arrive at this consistent view, we admittedly had to introduce an extension of the field equations of gravita-tion which is not justified by our actual knowledge of grav-

1 The spatial geometry in Einstein's model is that of a three-sphere, i.e., the surface of a sphere in four-dimensional Euclidean space. This is a prototype of a highly symmetric compact manifold without boundary.

itation. It has to be emphasized, however, that a positive curvature of space is given by our results, even if the sup-plementary term is not introduced. That term is necessary only for the purpose of making possible a quasi-static distri-bution of matter, as required by the fact of the small veloci-ties of the stars."

To de Sitter he emphasized in a letter on 12 March 1917, that his cosmological model was intended primarily to set-tle the question "whether the basic idea of relativity can be followed through its completion, or whether it leads to con-tradictions". And he adds whether the model corresponds to reality was another matter.Only later Einstein came to realize that Mach's philosophy is predicated on an antiquated ontology that seeks to re-duce the metric field to an epiphenomenon of matter. It became increasingly clear to him that the metric field has an independent existence, and his enthusiasm for what he called Mach's principle later decreased. In a letter to F. Pi-rani he wrote in 1954: "As a matter of fact, one should no longer speak of Mach's principle at all." GR still preserves some remnant of Newton’s absolute space and time.

De Sitter model

Surprisingly to Einstein, de Sitter discovered in the same year, 1917, a completely different static cosmological mod-el which also incorporated the cosmological constant, but was anti-Machian, because it contained no matter [6]. For this reason, Einstein tried to discard it on various grounds (more on this below). The original form of the metric was:

1 ( )-( ) singRr dt

Rr

dr d dr1 22

22

2

2 2j j {=- - + ++ ^ h8 B .

Here, the spatial part is the standard metric of a three-sphere of radius R, with R = (3/L)1/2. The model had one very interesting property: For light sources moving along static world lines there is a gravitational redshift, which became known as the de Sitter effect. This was thought to have some bearing on the redshift results obtained by Slipher. Because the fundamental (static) worldlines in this model are not geodesic, a freely-falling object released by any static observer will be seen by him to accelerate away, generating also local velocity (Doppler) redshifts corre-sponding to peculiar velocities. In the second edition of his book [7], published in 1924, Eddington writes about this:"de Sitter's theory gives a double explanation for this mo-tion of recession; first there is a general tendency to scat-ter (...); second there is a general displacement of spectral lines to the red in distant objects owing to the slowing down of atomic vibrations (...), which would erroneously be inter-preted as a motion of recession."I do not want to enter into all the confusion over the de Sitter universe. One source of this was the apparent singularity at r = R = (3/L)1/2. This was at first thoroughly misunderstood even by Einstein and Weyl. ("The Einstein-de Sitter-Weyl-Klein Debate" is now published in Vol. 8 of the Collected Papers [4].) At the end, Einstein had to acknowledge that de Sitter's solution is fully regular and matter-free and thus indeed a counter example to Mach's principle. But he still discarded the solution as physically irrelevant because it is not globally static. This is clearly expressed in a letter

Edwin Hubble

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from Weyl to Klein, after he had discussed the issue during a visit of Einstein in Zürich [8]. An important discussion of the redshift of galaxies in de Sitter's model by H. Weyl in 1923 should be mentioned. Weyl introduced an expanding version 2 of the de Sitter model [9]. For small distances his result reduced to what later became known as the Hubble law. Independently of Weyl, Cornelius Lanczos introduced in 1922 also a non-stationary interpretation of de Sitter's solution in the form of a Friedmann spacetime with a posi-tive spatial curvature [10]. In a second paper he also de-rived the redshift for the non-stationary interpretation [11].

From static to expanding world models

Until about 1930 almost everybody believed that the Universe was static, in spite of the two fundamental pa-pers by Friedmann [12] in 1922 and 1924 and Lemaî-tre's independent work [13] in 1927. These path break-ing papers were in fact largely ignored. The history of this early period has - as is often the case - been dis-torted by some widely read documents. Einstein too accepted the idea of an ex-

panding Universe only much later. After the first paper of Friedmann, he published a brief note claiming an error in Friedmann's work; when it was pointed out to him that it was his error, Einstein published a retraction of his com-ment, with a sentence that luckily was deleted before pub-lication: "[Friedmann's paper] while mathematically correct is of no physical significance". In comments to Lemaître during the Solvay meeting in 1927, Einstein again rejected the expanding universe solutions as physically unaccept-able. According to Lemaître, Einstein was telling him: "Vos calculs sont corrects, mais votre physique est abominable". It appears astonishing that Einstein - after having studied carefully Friedmann's papers - did not realize that his static model is unstable, and hence that the Universe has to be expanding or contracting. On the other hand, I found in the archive of the ETH many years ago a postcard of Einstein to Weyl from 1923, related to Weyl's reinterpretation of de Sitter's solution, with the following interesting sentence: "If there is no quasi-static world, then away with the cosmo-logical term".It also is not well-known that Hubble interpreted in 1929 the redshifts of radiation emitted by distant 'nebulae' in the framework of the de Sitter model, as had been suggested by Eddington.

Lemaître discovers the expanding universe

We repeat what we said in [1] about Lemaître's key role in the founding period of cosmology. He was the first per-son who seriously proposed an expanding universe as a model of the real universe. He derived in his crucial paper of 1927 the general redshift formula, and showed that it leads

2 The de Sitter model has many different interpretations, depending on the choice of the velocity field for the subdominant matter flow.

for small distances to a linear relation, known as Hubble's law. He also estimated the Hubble constant H0 based on Slipher's redshift data for about 40 nebulae, and Hubble's 1925 distance determination to Andromeda, as well as the the magnitudes of nebulae published by him in 1926. Two years before Hubble he found a value only somewhat high-er than the one Hubble obtained in 1929. (Actually, Lemaître gave two values for H0.) But this seminal work was almost completely ignored. The general attitude is well illustrated by the following remark of Eddington at a Royal Society meeting in January, 1930: "One puzzling question is why there should be only two solutions. I suppose the trouble is that people look for static solutions."Lemaître, who had been for a short time a post-doctoral student of Eddington, read this remark in a report on the meeting published in Observatory, and wrote to Eddington pointing out his 1927 paper. Eddington had seen that pa-per, but had completely forgotten about it. But now he was greatly impressed and recommended Lemaître's work in a letter to Nature. He also arranged for a translation which appeared in MNRAS [13]. Eddington also "pointed out that it was immediately deducible from his [Lemaître's] formulae that Einstein's world is unstable, so that an expanding or a contracting universe is an inevitable result of Einstein's law of gravitation."Lemaître's successful explanation of Hubble's improved data, carefully analysed by de Sitter in a series of papers, finally changed the viewpoint of the majority of workers in the field. At this point, after a stay with Eddington, and a visit to the Mount Wilson Observatory, Einstein rejected the cos-mological term as superfluous and no longer justified [14]. At the end of the paper in which he published his new view,

Alexander Friedmann

Letter from Lemaître to Eddington

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Einstein adds some remarks about the age problem which was quite severe without the L-term, since Hubble's value of the Hubble parameter was then about seven times too large. Einstein is, however, not very worried and suggests two ways out. First he says that the matter distribution is in reality inhomogeneous and that the approximate treat-ment may be illusionary. Then he adds that in astronomy one should be cautious with large extrapolations in time.After the L-force was rejected by its inventor, other cosmol-ogists, such as Eddington and Lemaître, retained it. One major reason was that it solved the problem of the age of the Universe when the Hubble time scale was thought to be only 2 billion years (corresponding to the value H0 ~ 500 km s-1 Mpc-1 of the Hubble constant). This was even shorter than the age of the Earth. In addition, Eddington and others overestimated the age of stars and stellar systems.For this reason, the L-term was employed again and a model was revived which Lemaître had singled out from the many solutions of the Friedmann-Lemaître equations 3. This so-called Lemaître hesitation universe is closed and has a repulsive L-force (L > 0), which is slightly greater than the value chosen by Einstein. It begins with a big bang and has the following two stages of expansion. In the first the

3 I recall that Friedmann included the L-term in his basic equations. I find it remarkable that for the negatively curved solutions he pointed out that these may be open or compact (but not simply connected).

L-force is not important, the expansion is decelerated due to gravity and slowly approaches the radius of the Einstein universe. At about the same time, the repulsion becomes stronger than gravity and a second stage of expansion be-gins which eventually inflates. In this way a positive L was employed to reconcile the expansion of the Universe with the age of stars.Lemaître was also the first who associated in 1933 the cosmological constant with vacuum energy. Actually, Pauli made before the advent of the new quantum mechanics some simple, but profound remarks on this issue [15].To a minority of cosmologists who had read the French original of Lemaître's 1927 paper, it was known that a few paragraphs were deleted in the translation, notably the one in which Lemaître assessed the evidence for linearity of the distance-velocity relation and estimated the expansion rate. Fortunately, the origin of this curious fact has very recently been completely cleared up [16]. It was Lemaître himself who translated his original paper. The correspondence of him with the editor of MNRAS, quoted in [16], shows that Lemaître was not very interested in establishing priority. He saw no point in repeating in 1931 his findings four years earlier, since the quality of the observational data had in the meantime been improved. This is one of the reasons that Hubble was elevated to the discoverer of the expanding universe.For much more on all this I refer again to the recent excel-lent book [17] of our Swiss colleagues Harry Nussbaumer and Lydia Bieri.

References

[1] N. Straumann, The 2011 Nobel Prize in Physics, SPG Mittei-lungen, Nr. 36, Januar 2012.[2] A. Sandage, Preface to [17].[3] A. Einstein, Sitzungsber. Preuss. Akad. Wiss. phys.-math. Klas-se VI, 142 (1917). See also: [4], Vol. 6, p. 540, Doc. 43.[4] A. Einstein, The Collected Papers of Albert Einstein, Vols. 1-12, Princeton University Press, 1987–. See also: [http://www. einstein.caltech.edu/].[5] A. Einstein, On the Foundations of the General Theory of Rela-tivity. Ref. [4], Vol. 7, Doc. 4.[6] W. de Sitter, Proc. Acad. Sci., 19, 1217 (1917); and 20, 229 (1917).[7] A. S. Eddington, The Mathematical Theory of Relativity. Chel-sea Publishing Company (1924). Third (unaltered) Edition (1975). See especially Sect.70.[8] Letter from Hermann Weyl to Felix Klein, 7 February 1919; see also Ref. [5], Vol. 8, Part B, Doc. 567.[9] H. Weyl, Phys. Zeits. 24, 230, (1923); Phil. Mag. 9, 923 (1930).[10] C. Lanczos, Phys. Zeits. 23, 539 (1922).[11] C. Lanczos, Zeits. f. Physik 17, 168 (1923).[12] A. Friedmann, Z.Phys. 10, 377 (1922); 21, 326 (1924).[13] G. Lemaître, L’univers en expansion. Ann. Soc. Sci. de Bru-xelles 47, 49 (1927). Translated in MNRAS 91, 483 (1931).[14] A. Einstein, S. B. Preuss. Akad. Wiss. (1931), 235.[15] N. Straumann, Wolfgang Pauli and Modern Physics, Space Science Reviews 148, 25 (2009).[16] M. Livio, Nature 479, 208-211 (2011).[17] H. Nussbaumer and L. Bieri, Discovering the Expanding Uni-verse, Cambridge University Press (2009).

Albert Einstein and Georges Lemaître

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Über den Einfluss des Lichtes auf den MenschenMit den beiden folgenden Artikeln dringen wir in das Gebiet der Biophysik ein. Was liegt näher im Jahrhundert des Pho-tons, als den Einfluss des Lichtes auf das menschliche Verhalten zu beschreiben? Vieles, was bislang nur empirisch erfasst werden konnte, kann heutzutage als Abfolge physikalisch/chemischer Zeitprozesse quantitativ erklärt und modelliert wer-den. Für die Beleuchtungsindustrie öffnet sich ein riesiges Aktionsfeld, um die Wirkung des Lichtes auf das Wohlbefinden des Menschen technisch umzusetzen.

Nicht-visuelle Lichtwirkungen beim Menschen

Christian Cajochen, Zentrum für Chronobiologie, Universität Basel

Ohne sichtbares Licht ist bewusstes Sehen für den Men-schen unmöglich. Einfallendes Licht wird in den Augen ge-sammelt und weiterverarbeitet, damit ein Abbild der Um-gebungswelt in unserem Gehirn entsteht. Die Netzhaut im Auge wandelt die eintreffenden Lichtimpulse in Nervensi-gnale um und leitet sie über den Sehnerv ans Gehirn wei-ter. Neben den Hirngebieten, die verantwortlich fürs Sehen sind, trifft die Lichtinformation auch auf Hirnregionen, die eine wichtige Rolle für die Regulierung circadianer (circa diem = ungefähr ein Tag) Rhythmen und der Verarbeitung von Gedächtnisinhalten und Emotionen spielen. Licht spielt somit eine zentrale "nicht-visuelle" Rolle, die zur Zeit in-tensiv auf dem Gebiet der Chronobiologie, der Schlaffor-schung, der Kognitionsforschung, aber zunehmend auch von Lichtplanern und Architekten erforscht wird.

Licht- mehr als nur fürs Sehen

Lichtwirkungen, die nicht unmittelbar mit dem Sehen zu-sammenhängen, werden als sogenannte nicht-visuelle Lichtwirkungen bezeichnet, welche folgend zusammenge-fasst sind.

1. Licht eicht die innere Uhr.Die Tagesrhythmik (Circadianrhythmik) ist eine Spontan-rhythmik, die eigentlich in jeder Körperzelle tickt, aber von einem reiskorngrossen Hirngebiet, das ca. 2 cm hinter der Nasenwurzel liegt, kontrolliert wird. Dieses Hirngebiet liegt in den sogenannten suprachiasmatischen Kernen und umfasst ungefähr 10 bis 20000 Nervenzellen, die als Schrittmacher fungieren, indem sie eine endogene Spon-tanaktivität mit einer Rhythmik von 24 Stunden generieren (Abbildung 1). Falls kein Licht vorhanden ist, oder Dauer-licht herrscht, misst man bei Menschen eine Spontanrhyth-mik, die im Durchschnitt etwas länger als 24 Stunden, näm-lich 24.2 Stunden beträgt. Die Periodenlänge ist individuell verschieden und zum Teil genetisch determiniert. So haben Frühtypen (Lerchen) eher kürzere als 24 Stunden Perio-denlängen, während Abendtypen (Eulen) eher langsamer > 24.8 Stunden ticken. Leben Menschen unter Dauerdunkel-heit (z.B. Sehbehinderte) oder Dauerlicht, laufen die Tages-rhythmen frei- gemäss der endogenen Periodik (Abbildung 1 oberes Beispiel). Das heisst, die Rhythmen sind nicht auf den Tag-Nachtwechsel abgestimmt. Der immer wie-derkehrende Licht-Dunkelwechsel, dem wir normalerwei-se täglich ausgesetzt sind, gleicht diese Spontanrhythmik

auf die exakte 24-Stunden Periodik der Erdrotation ab (Abbildung 1 un-teres Beispiel). Licht wirkt deshalb als Zeitgeber. Zuwenig Licht für ei-nige Zeit, oder Licht zur falschen Zeit (z.B. bei der Schichtarbeit), bringt die innere Uhr aus dem Lot mit dem natürlichen 24-Stunden-Licht-Dunkelwechsel, was zu circa-dianen Schlafstörungen führt. Das geschieht sehr oft bei Leuten mit Sehbehinderungen, bei Schichtar-beitern oder wenn man nach dem Überfliegen von mehreren Zeitzo-nen mit einem "Jetlag" zu kämpfen hat. Folgen einer dauernden circadi-anen Desynchronisation sind neben Schlafstörungen auch gastrointesti-nale Beschwerden, Depressionen und kardiovaskuläre Störungen. Do-sis Wirkungsstudien haben ergeben, dass beim Menschen Lichtstärken ab ca. 100 lux wirksam sind für die Eichung der inneren Uhr (Abbildung 2). Mit Morgenlicht verschiebt man die innere Uhr nach vorne, also in eine östliche Zeitzone, während

Abbildung 1. Die Eichung der inneren Uhr durch Licht. Die endogene Circadianrhythmik wird in den suprachiasmatischen Kernen (SCN), einem Hirngebiet im vorderen Hypothalamus, ge-neriert. Das Signal wird über den paraventrikulären Nukleus (PVN), über das superiore Zervi-kalganglion im Rückenmark (SCG) zur Pinealis, dem Ort der Melatoninproduktion weitergelei-tet. Die Sekretion des Hormons Melatonin ist tagesrhythmisch unter der Kontrolle der SCN. Falls Dauerlicht oder Dauerdunkelheit aufs Auge fällt, ist der Tagesgang des Melatonins nicht synchronisiert und läuft „frei“, gemäss der endogenen Circadianperiodik, die von 24 Stun-den abweicht (oberes Beispiel). In diesem Beispiel verzögert sich die Melatoninproduktion jeden Tag um ca. 0.8 Stunden, weil die endogene Tagesperiodik 24.8 Stunden beträgt. Falls der periodische Licht-Dunkelwechsel, der durch die Erdrotation genau 24 Stunden beträgt, wahrgenommen wird, wird dieses Signal vom Auge, über die Netzhaut, via den retinohypo-thalamischen Trakt (RHT) direkt zu den SCN weitergeleitet. Dieser Licht-Dunkelwechsel wirkt als Zeitgeber, das heisst die Endogenperiodik wird auf die Exogenperiodik des 24-Stunden Lichtdunkelwechsel abgeglichen, man spricht von circadianem „Entrainment“.

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Licht am Abend die innere Uhr zurückverschiebt in eine westliche Zeitzone. Mit einem einzigen Lichtpuls von 10000 lux für 3 Stunden kann man die Circadianrhythmik bis zu 2 Stunden vor- bzw. nachverschieben.

2. Licht macht wach.Eine tagaktive Spezies wie der Mensch empfindet das Licht als "Wachstimulus". Im Gegensatz dazu wirkt Licht bei nachtaktiven Tieren schlafinduzierend. Ab etwa 100 lux wirkt Licht bei jungen Menschen wachheitssteigernd. Das entspricht einer nicht allzu starken Raumbeleuchtung. Diese Helligkeit kann aber schon vor einem Computer-bildschirm sitzend erreicht werden. Neben der Lichtstär-ke spielt auch die Wellenlänge, also die farbliche Zusam-mensetzung des Lichts, eine wichtige Rolle. So hat Licht mit hohen Blauanteilen eine stärkere wachheitssteigernde Wirkung als Licht in anderen Farben, weil spezielle Licht-rezeptoren in der Netzhaut besonders bei Blaulicht aktiv werden, und so die nicht-visuellen Lichtwirkungen gezielt auf das Gehirn weitervermitteln. Es wird vermutet, dass die Rezeptoren für die nicht-visuellen Lichtwirkungen eng mit den klassischen visuellen Rezeptoren, den Stäbchen und Zäpfchen, kommunizieren. Je nach Lichtstärke und Dau-er des Lichtstimulus beteiligen sich Stäbchen, Zäpfchen oder sogenannte "intrinsisch photosensitive Ganglienzellen in der Netzhaut" unterschiedlich stark an der Vermittlung nicht-visueller Lichtwirkungen.

3. Licht macht helle.Neue Untersuchungen zeigen, dass Licht auch direkte Auswirkungen auf die kognitive Leistungsfähigkeit von Menschen hat. Wir konnten zum Beispiel feststellen, dass Versuchspersonen, die eine Lernaufgabe vor einem mit Leuchtdioden (LED) mit vielen Blauanteilen bestückten

Computerbildschirm besser lösten, als wenn sie die glei-che Aufgabe vor einem "normalen" Computerbildschirm ohne LEDs der gleichen Lichtstärke meistern mussten (Ab-bildung 3). Neben dem Gedächtnis für deklaratives Lernen werden auch sogenannt höhere kognitive Funktionen im Bereich der Exekutivkontrolle und der Daueraufmerksam-keit mit blauangereichertem Licht im Vergleich zu Glühlam-penlicht verbessert.

4. Licht wirkt antidepressiv.Die Lichttherapie ist das Mittel erster Wahl bei der Behand-lung von Winterdepressionen, und deren Kosten werden schon seit über 20 Jahren von den Schweizerischen Kran-kenkassen vergütet. Zudem zeigen neue Studien, dass Licht auch bei anderen psychiatrischen Erkrankungen an-tidepressiv und gegen die häufige Tagesmüdigkeit wirkt. Hier ist der Wirkungsmechanismus weitgehend unbekannt. Neuere Untersuchungen mit bildgebenden Verfahren für die Hirnaktivitätsmessung zeigen, dass Licht direkt auf die so-genannten Mandelkerne wirkt. Das ist ein wichtiges Hirn-gebiet für die Verarbeitung von Gefühlen und Emotionen.

Konsequenzen für das Licht am Arbeitsplatz

Am Arbeitsplatz müssen die Lichtbedingungen vor allem bezüglich visuellem Komfort optimal abgestimmt werden. In letzter Zeit spielen aber auch die nicht-visuellen Lichtwir-kungen zunehmend eine grössere Rolle. Aufgrund der neu-en Forschungsresultate wie Lichtqualität und Wohlbefinden zusammenhängen, hat die Lampenindustrie ein neues Ge-schäftsfeld entdeckt. So erhofft man sich positive Effekte auch von besserem Licht am Arbeitsplatz. Ob diese Hoff-nung berechtigt ist, haben Forscher der Universität Surrey in einem Bürogebäude in England untersucht. Sie bestrahl-ten je ein Stockwerk zuerst vier Wochen mit weissem Licht und dann vier Wochen mit blau angereichertem Licht oder umgekehrt. Sowohl Aufmerksamkeit als auch Gemütsla-ge, Leistung, Konzentration und Sehkomfort waren beim blauweissen Licht signifikant verbessert. Auch konnten die Probanden in der Nacht besser schlafen. Wichtige Licht-quellen im Büro sind nicht nur Lampen, sondern auch die Bildschirme. Biologisch besonders aktiv sind Modelle der neueren Generation mit LEDs, denn sie emittieren stark im blauen Wellenlängenbereich. Neben der geistigen Lei-stungsfähigkeit wie oben erwähnt, wirken LED Bildschirme auch auf physiologische Messgrössen beim Menschen wie zum Beispiel die abendliche Produktion des Dunkelhor-mons Melatonin und die elektro-enzephalographisch ge-messene Hirnaktivität (siehe 1).Neben der Lichtgestaltung mit künstlichem Licht im Büro ist aber auch der Einbezug von natürlichem Tageslicht sehr wichtig. Schon 1971 definierte der Biologe Stephen Boyden das Bedürfnis nach Tageslicht als eine der "well-being needs": als Voraussetzung für ein Leben ohne stressbe-dingte Krankheiten. Man weiss, dass Mitarbeiter, die wenig Tageslicht abbekommen, unzufriedener und gesundheitlich anfälliger werden (Berliner Ergonomic Instituts für Arbeits- und Sozialforschung). Darum arbeiten Physiker, Lichtplaner, Architekten und Chronobiologen fieberhaft an ausgeklügel-ten Systemen und Gebäudegrundrissen, um das Tageslicht bis in hinterste Zimmerwinkel zu leiten. Eine ideale Lösung wäre, eine biodynamische Lichtquelle am Arbeitsplatz zu haben, die punkto Intensität und Wellenlänge (Farbe) dem

Abbildung 2. Dosis-Wirkungs-beziehung zwischen der Be-leuchtungsstärke und der pha-senverschiebenden Wirkung von Licht nach Zeitzer 1999. Jedes Quadrat symbolisiert eine Versuchsperson, die während 6.5 Stunden mit je einer un-terschiedlichen Lichtstärke (2-10000 lux) bestrahlt wurde.

Abbildung 3. Positive Wirkung von LED Com-puterbildschirmen auf höhere kognitive Funk-tionen im Vergleich zu nicht-LED Computer-bildschirmen, die we-niger Blauanteile im Lichtspektrum haben.

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natürlichen Wechsel des Tagelichts möglichst nahe kommt. Denn evolutionsgeschichtlich gesehen, wurde der Mensch nicht fürs Büro konzipiert. Für uns wäre es normal, wenn wir tagsüber draussen im Hellen wären. Einen sehr inno-vativen Ansatz, dieses Dilemma zu entschärfen, kommt derzeit vom Fraunhofer Institut, das eine dynamische Licht-decke mit Tausenden kleiner LEDs entwickelt hat, welche dem Büroangestellten das Gefühl vermittelt, unter freiem Himmel zu arbeiten (http://www.fraunhofer.de/en/press/re-search-news/2012/january/sky-light-sky-bright.html). Erste Untersuchungen zeigen, dass ein solches Lichtszenario vor allem bei der Verrichtung von kreativen Arbeiten am Com-puter auf grossen Anklang stösst.Neben dieser kreativen technischen Lösung der Bürobe-leuchtung versucht man eine nüchterne Vornorm zu erstel-len, um die wichtige Begriffe zur cirkadianen, nicht-visu-ellen Wirkung von Licht auf den Menschen zu klären (DIN V 5031-100). Das Ziel ist es, aufzeigen, wann und wie bio-logisch wirksame Beleuchtung einzusetzen ist, und wie viel wirksamer sie ist als normales Licht. Viele Forscher glauben

allerdings, dass es für eine solche Richtlinie noch zu früh ist. Es sind noch zu viele Fragen offen, und es mangelt an Studienergebnissen, um sich derart festzulegen. Es ist aber sehr positiv, dass neben den visuellen Aspekten nun ver-mehrt die Wirkungen des Lichts auf die innere Uhr und de-ren Regulation des Schlaf-Wachrhythmus, der kognitiven Leistung sowie der Stimmung berücksichtigt werden, denn Licht ist mehr als nur Helligkeit.

Prof. sc. natw. Christian Cajochen leitet das Zentrum für Chronobiologie an der Psychiatrischen Universi-tätsklinik in Basel. Seine Forschungsinteressen um-fassen die circadiane und homöostatische Regulation der Schlaf/Wachrhythmik beim Menschen, die nicht-visuelle Lichtwirkung in der Chronobiologie, sowie circadiane Schlaf-Wachstörungen bei psychiatrischen Patienten.

Lighting Application for Non-Visual Effects of Light

Andreas Wojtysiak, Alfred Wacker and Dieter Lang, Osram AG

IntroductionThe discovery of melanopsin containing retinal ganglion cells with intrinsic photoreception (ipRGC) at the beginning of this millennium [1, 2, 3] evoked interest not only in the research community, but also in the lighting industry. Ben-eficial health effects of light have been discussed not only since evidence for the use of light in psychiatric disorder therapy was achieved. One obvious drawback for broader application was always the need for additional energy, be-cause clear effects with the typical light used for illumina-tion purposes were dependent on higher illumination levels. It now has turned out, that the lighting used in previous lab-oratory and application studies was not sufficiently adapt-ed to the non-visual reception system and cofactors could have masked these effects considerably. Though there is still discussion about the optimal lighting for non-visual ef-fects with minimum energy use, there is no doubt in the scientific community that appropriately timed stimulation of the ipRGC during the day and avoidance of stimulation in the night stabilizes our circadian system. This leads to a more efficient nocturnal sleep and better daytime activity and alertness levels. Alertness is also directly affected by input to the ipRGCs, resulting in acutely increased perform-ance in laboratory testing and higher activity levels in cor-responding nuclei of the brain [4]. This article will highlight how to transfer scientific results on non-visual effects - also called biological effects - of light into lighting application.

Lighting Technology for non-visual effectsLight SourcesA number of studies on the ipRGC have shown that the action spectrum of their photopigment melanopsin peaks in the blue spectrum around 480 nm. No nervous cell re-sponses were elicited by yellow or red light. The best de-scribed action spectrum for a more complex biological re-

sponse is the curve for nocturnal melatonin suppression. Several models have been developed to describe this re-sponse with minor deviations when these were used to rate white light with respect to its circadian input. The models of Gall [5] and Rea [6] differ with respect to the effect of light in the green wavelength region, which might be of interest when comparing small waveband (colored) light sources. In total, it can clearly be stated, that blue spectral compo-nents in light act on the internal clock system by affecting circadian amplitude and phase.

The model from Gall [5] was implemented in the German prestandard DIN V 5031-100:2009 [7], which contains terms and definitions for biological effects of light. Us-ing the metrics described there, it is possible to rate lamp spectra according to their biological efficiency in addition to light output for vision. A lamp spectrum with a higher so-called biological action factor (abiol v ≥ 0,8) has a high frac-tion of short wavelength spectrum, a high correlated color

Fig. 1: action spectrum c() for biological effects and visual sensi-tivity curve v() combined from different sources.

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temperature, and is generally more suitable to represent the active and day time part of the circadian day, especially in the morning hours. Cool white light sources including LEDs and fluorescent lamps may be used for this purpose. While stabilizing circadian rhythms when applied over the day, this spectrum is not suited for the regenerative and noc-turnal phases, typically in the late evening and night. Warm white lamps with low biological action factors (abiol v ≤ 0,4) have a lower influence on the ipRGCs and on the internal clock. These lamps are more suited when light for vision is needed, but an influence on the circadian phase or an alert-ing effect should be avoided. Halogen lamps, warm white LEDs or fluorescent lamps are suited to achieve this.

To balance best with visual and ecological needs, it seems advisable to use different CCT lamps or light sources with high energy efficiency over the day and use them as need-ed. This will result in higher installation costs in the short term, but will be the most sustainable solution in the long run.

LuminairesThe biological photoreceptors are widely distributed over the eye’s retina and more sensitive in the nasal and inferior region than in the upper part [8]. For biological effects it is essential to address many of these receptors, like the sky does in nature. Good effects indoors will be achieved with light coming from the upper field of view and covering a wide solid angle, e. g. from the ceiling and the upper sur-faces of walls. Consequently, biologically effective illumina-tion requires planning and luminaires fitting to this concept, with a high proportion of indirect lighting or laminar design, thus leading to suitable vertical illumination levels. Up to now, no dose-response curve describing the relationship between lighting area and biological effect size has been established. In the meanwhile, the general recommenda-tion for application must be to "maximize" the lighting area, while keeping luminance levels low in order to avoid glare effects.

Controls and Light Management Systems (LMS)Natural daylight is highly variable, especially in terms of il-luminance levels but also in terms of color temperature. It

is clear that the dynamics of daylight follows a rhythmic change in the course of day and night, and that this is a benchmark for good artificial lighting also. For day time ap-plication, changes in biological efficiency of applied lighting with positive impact on circadian rhythm stability, sleep/wake cycle, alertness and cognitive performance can be achieved with light management technology already avail-able. The biological effectiveness in nature emanates from a combination of spectral composition and illuminance level, being in average at highest level around noon and at minimum in the night. Technically, this situation can be sim-ulated by dimming the relative contribution of lamps with different light colors against each other in order to have a white light color but with different portions of blue spectral components appropriate to the respective daytime.

Warm colors with only little biological effects can maintain good vision without strongly influencing circadian effects in the evening, while cooler colors with enriched blue con-tent used over the day are providing good vision and higher biological effectiveness simultaneously. The evening and night scenario also allows to reduce the laminar light dis-tribution and a change to spot-like illumination exclusively. This allows also substantial reductions in amount of energy needed for lighting, as only the visual tasks and emotional aspects have to be respected in these hours. Reductions in energy consumption may further be achieved by includ-ing sensors and intelligent controls, without deductions in illumination quality.

Lighting Application StudiesApplication studies (like the examples below) showed, that non-visual effects of light may be achieved with moderate effort in energy consumption by using modern lighting sys-tems and control. The general strategy is to differentiate lighting according to time of the day and needs.

Better lighting in nursing homes improved the nocturnal sleep and daytime activity as well as psychological scores of elderly persons in several studies [9, 10]. Old persons are especially dependent on a lighting change because of their reduced transmission of the dioptric apparatus. The hazing and yellowing of the lenses with age reduces drastically the

Fig. 2: Lighting concept with pendant luminaires for day-time of-fice workers including non-visual effects of light:Left: Day scenario with task lighting by warm white direct light and

additional cool white light to the ceiling and upper wall to address ipRGC. Right: Evening and night scenario with warm white task lighting only.

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short wavelength light arriving at the retina. This effect was counteracted by the lighting.

A stronger synchronization by daytime office light and im-provements in subjective performance in office workers have been achieved with fluorescent lamps of higher CCT than the typical 4000 K lamps used in this application [11, 12]. For daytime indoor workers, this could be a first step to a better lighting but it is needed to say that this scenario might not be optimal for late office hours.

Comparable benefits have been shown in schools, lead-ing to increased scholar performance of the pupils and in hospital settings, where the recovery phase could be short-ened.

ConclusionAlthough scientific researchers still have numerous ques-tions in this field, these first results of application of the new findings on non-visual effects of light open a very promis-ing future for improvements in interior illumination. This is true for the professional lighting as well as for the lighting at home.

References[1] Brainard, G. C., et al. (2001). "Action spectrum for melatonin regulati-on in humans: evidence for a novel circadian photoreceptor." J Neurosci 21(16): 6405-12.[2] Thapan, K., et al. (2001). "An action spectrum for melatonin suppressi-on: evidence for a novel non-rod, non-cone photoreceptor system in hu-mans." J Physiol 535 (Pt 1): 261-7.[3] Berson, D. M., et al. (2002). "Phototransduction by retinal ganglion cells that set the circadian clock." Science 295(5557):1070-3.[4] Vandewalle, G., P. Maquet, et al. (2009). "Light as a modulator of cogni-tive brain function." Trends Cogn Sci 13(10): 429-38.[5] Gall, D., Bieske, K. (2004). Definition and measurement of circadian radiometric quantities. CIE Symposium '04: Light and Health: non-visual effects, University of Performing Arts, Vienna, CIE.[6] Rea, M. S., et al. (2005). "A model of photo¬transduction by the human circadian system." Brain Res Brain Res Rev 50(2): 213-28.[7] DIN V 5031-100:2009-06 Optical radiation physics and illuminating en-gineering - Part 100: Non-visual effects of ocular light on human beings - Quantities, symbols and action spectra [8] Glickman, G., et al. (2003). "Inferior retinal light exposure is more effec-tive than superior retinal exposure in suppressing melatonin in humans." J Biol Rhythms 18(1):71-9.[9] Van Someren, E. J., A. Kessler, et al. (1997). "Indirect bright light impro-ves circadian rest-activity rhythm disturbances in demented patients." Biol Psychiatry 41(9): 955-63.[10] Riemersma-van der Lek, R. F., D. F. Swaab, et al. (2008). "Effect of bright light and melatonin on cognitive and noncognitive function in elder-ly residents of group care facilities: a randomized controlled trial." JAMA 299(22): 2642-55.[11] Vetter, C., M. Juda et al. (2011) “Blue-enriched office light competes with natural light as a zeitgeber”; Scand J Work Environ Health 37(5): 437-445[12] Viola, A. U., L. M. James, et al. (2008). "Blue-enriched white light in the workplace improves self-reported alertness, performance and sleep quality." Scand J Work Environ Health 34(4): 297-306.

Andreas Wojtysiak ist promovierter Biologe und nach Tätigkeiten am IMST in Kamp-Lintfort, in der Medizi-nischen Fakultät der privaten Universität Witten/Her-decke und bei BenQ Mobile in München seit 2008 bei der Osram AG München als Innovation Manager Light & Health beim Strategic Innovation Management (SIM) aktiv.

Alfred Wacker (Dipl.-Ing.) war früher Leiter des Mar-ketings bei OSRAM und ist nun für seine Firma be-ratend und in internationalen Gremien und Komitees tätig, u. A. im "Lighting Technology Standards Com-mittee NA 058-00-27 AA (FNL 27) 'Effects of light on human beings' at DIN", dem auch die Schweiz ange-hört.

Dieter Lang (Dipl.-Phys.) forschte früher bei Osram an "ceramic metal halide lamps" und ist seit der For-mierung des Corporate Innovation Management De-partment im Jahr 2004 als Head Europe zuständig für Innovationen.

Jet Lag and Shift Work

Natural light sets the internal clock, but humans of-ten challenge this system with more or less volunta-ry changes in day/night behavior. Jet travel is such a challenge, shift work is another. The internal clock shifts about 1 hr per day in such scenarios. With timed biologically active light (as described in the main text) and avoidance of light at other appropriate times, it appears possible to adapt to a new time zone much faster. Shifts of more than 3 hrs with one light episode have been achieved in laboratory settings [a]. But at present, there is no reliable and robust scientific base how to handle lighting for shift workers. Actual recom-mendations range from shortening the shift schedules in order to reduce frequent massive circadian disrup-tion as stated by some ergonomics experts to shif-ting totally (also in the worker’s free times) to the new shift schedule as proposed by chronobiologists, with considerable consequences for social life of those af-fected [b].

[a] Khalsa, S. B., M. E. Jewett, et al. (2003). "A phase response curve to single bright light pulses in human subjects." J Physiol 549 (Pt 3): 945-52.[b] Roenneberg, T. (2009): "New approaches in investigating the consequences of shift-work". 3rd DIN Expert Panel Effect of Light on Human Beings, DIN. Berlin, Beuth Verlag.

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SPG MITTEILUNGEN COMMUNICATIONS DE LA SSP · 16. Juni 2011 Procès-verbal de l'assemblée générale du 16 juin 2011 2. Kurzer Bericht des Präsidenten Bref rapport du président