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Geometrical and electronic structure at and near surfaces

English title Geometrical and electronic structure at and near surfaces
Applicant Aebi Philipp
Number 147198
Funding scheme Project funding
Research institution Département de Physique Université de Fribourg
Institution of higher education University of Fribourg - FR
Main discipline Condensed Matter Physics
Start/End 01.04.2013 - 31.03.2015
Approved amount 456'028.00
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Keywords (10)

selfassembly; Oxide-based materials; angle-resolved photoemission; transition metal dichalcogenides; low energy electron diffraction; Fermi surface mapping; scanning tunneling microscopy and spectroscopy; surfaces; low dimensional systems; nanostructures

Lay Summary (German)

Lead
Bei diesem Projekt geht es um Grundlagenforschung auf dem Gebiet der Elektronenstruktur und der Anordnung der Atome im Festkörper und an Oberflächen. Das Hauptziel ist es neues Wissen zu kreieren und ein besseres quantenmechanisches Verständnis über Prozesse im sub-nanometer Bereich zu erarbeiten. Forschung auf diesem Gebiet ist höchst relevant für Entwicklungen im Bereich neuer Materialien.
Lay summary

Inhalt und Ziel

 Wir werden winkelaufgelöste Photoemissions- und Rastertunnelmikroskopie / Spektroskopie Experimente an einkristallinen Materialien machen. Die Experimente finden im Ultrahochvakuum statt da sie extrem oberflächenempfindlich sind. Messungen werden mit Festkörperrechungen basierend auf der Quantenmechanik komplettiert. Die Photoemission erlaubt es durch das Messen der Winkelverteilung der emittierten Elektronen herauszufinden wie die Elektronen im Material verteilt sind (in Energie und Impuls). Dies ist wichtig weil die Elektronenverteilung die Eigenschaften des Materials bestimmt. Da die Elektronen auf ihrem Weg ins Vakuum an den Atomen des Kristalls streuen, entsteht ein Interferenzmuster das zur Untersuchung der Atompositionen benutzt werden kann. Die Rastertunnelmikroskopie und Spektroskopie erlaubt ebenfalls das Untersuchen der Elektronenstruktur, dies aber sehr lokal (Nanometer) im Gegensatz zur Photoemission wo über einen grösseren Bereich (Millimeter) gemittelt wird. Die beiden Methoden sind daher komplementär. Das Ziel ist es besser zu Verstehen was der Grund ist, dass Atome sich in einer gewissen Struktur anordnen oder dass ein Phasenübergang stattfindet.

 

Wissenschaftlicher und gesellschaftlicher Kontext

 Unsere Arbeit liefert neue Ergebnisse im fundamentalen Verständnis der kondensierten Materie. Es geht darum neues Wissen zu kreieren das aber nicht sofort zu neuen Anwendungen führt. Wichtig ist auch das Training der Mitarbeiter im Arbeiten mit komplexen Instrumenten und Problemen. Dies ist in jeder hochqualifizierten, zukünftigen Arbeitsstelle von grossem gesellschaftlichen Nutzen. 
Direct link to Lay Summary Last update: 28.03.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Excited states at interfaces of a metal-supported ultrathin oxide film.
T. Jaouen et al. (2015), Excited states at interfaces of a metal-supported ultrathin oxide film., in Phys. Rev. B, 91, 161410(R).
Impact of electron-hole correlations on the 1T-TiSe2 electronic structure
Monney G., Monney Claude, Hildebrand B., Aebi Philipp, Beck H. (2015), Impact of electron-hole correlations on the 1T-TiSe2 electronic structure, in Physical Review Letters, 114(8), 1.
Comprehensive study of the spin-charge interplay in antiferromagnetic La-2 - xSrxCuO4
Drachuck Gil, Razzoli Elia, Bazalitski Galina, Kanigel Amit, Niedermayer Christof, Shi Ming, Keren Amit (2014), Comprehensive study of the spin-charge interplay in antiferromagnetic La-2 - xSrxCuO4, in NATURE COMMUNICATIONS, 5, 1.
Doping Nature of Native Defects in 1T-TiSe2
Hildebrand B., Didiot Clément, Novello Alberto M., Monney G., Scarfato Alessandro, Ubaldini Alberto, Berger Helmuth, Bowler David R., Renner Ch H., Aebi Philipp (2014), Doping Nature of Native Defects in 1T-TiSe2, in Physical Review Letters, 112(19), 1.
Fate of the excitonic insulator in the presence of phonons
Zenker B., Fehske Holger, Beck Hans G E (2014), Fate of the excitonic insulator in the presence of phonons, in Physical Review B - Condensed Matter and Materials Physics, 90(19), 1.
Induced work function changes at Mg-doped MgO/Ag(001) interfaces: Combined Auger electron diffraction and density functional study
Jaouen T., Aebi Philipp, Tricot Sylvain, Delhaye G., Lépine Bruno, Sébilleau Didier, Jézéquel Guy, Schieffer P. (2014), Induced work function changes at Mg-doped MgO/Ag(001) interfaces: Combined Auger electron diffraction and density functional study, in Physical Review B - Condensed Matter and Materials Physics, 90(12), 1.
Layer-resolved study of Mg atom incorporation at the MgO/Ag(001) buried interface
Jaouen T., Tricot Sylvain, Delhaye G., Lépine Bruno, Sébilleau Didier, Jézéquel Guy, Schieffer P. (2013), Layer-resolved study of Mg atom incorporation at the MgO/Ag(001) buried interface, in Physical Review Letters, 111(2), 1.
Quasi one-dimensional Ag nanostructures on Si(331)–(12 × 1)
N. Mariotti et al., Quasi one-dimensional Ag nanostructures on Si(331)–(12 × 1), in Surf. Sci..

Collaboration

Group / person Country
Types of collaboration
Th. Schmitt, PSI Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
Th. Greber, J. Osterwalder, UniZh Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
C. Monney, Fritz-Haber, Berlin Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
J.-M. Triscone, Geneva Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
C. Bernhard, UniFR Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
R. Fasel, empa Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
Ph. Schieffer, G. Jézéquel, IPR, Rennes France (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
H. Berger, L. Forro, EPFL Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
E. Schwier, K. Shimada, Hiroshima Japan (Asia)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Ch. Renner, A. Ubaldini, UniGe Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
M. Muntwiler, Th. Jung, PSI Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Invited Seminar, Institut de Physique de Rennes (IPR) Individual talk Layer-Resolved Resonant Auger Spectroscopy to Probe the Nature of a Metal-Supported Ultrathin Oxide Film 10.04.2015 Rennes, France, France Jaouen Thomas;
SPS annual meeting Talk given at a conference Doping nature of native defects in 1T-TiSe2 30.06.2014 Fribourg, Switzerland Hildebrand Baptiste;
Frimat Day 2014 Talk given at a conference Electronic nature of a Metal-Supported Ultrathin Insulating Film Tracked by Resonant Auger Spectroscopy 27.06.2014 Fribourg, Switzerland Jaouen Thomas;
Frimat Day 2014 Poster New photoemission and STM setup 27.06.2014 Fribourg, Switzerland Monney Gaël;


Communication with the public

Communication Title Media Place Year
Media relations: print media, online media Forscher entdecken Schwächen bei Supraleiter German-speaking Switzerland Western Switzerland 2014
Video/Film Prof. Dr Philipp Aebi - Solid state physicist - Unifr.ch Western Switzerland 2014

Awards

Title Year
Baptiste Hildebrand a obtenu le Prix Vigener 2013 de la Faculté des sciences pour son travail de master en physique, intitulé «Introduction aux functions de Green en seconde quantification ainsi qu'aux techniques de microscopie et spectroscopie tunnel: Application à l'étude du 1T-TiSe2» 2013

Associated projects

Number Title Start Funding scheme
159753 Geometrical and electronic structure at and near surfaces 01.04.2015 Project funding
128686 Towards a more bulk sensitive photoemission experiment 01.06.2010 R'EQUIP
134890 Geometrical and electronic structure at and near surfaces 01.04.2011 Project funding
134890 Geometrical and electronic structure at and near surfaces 01.04.2011 Project funding
159753 Geometrical and electronic structure at and near surfaces 01.04.2015 Project funding

Abstract

Context and significance:The project focuses on fundamental physics concerning the atomic and electronic structure. The main goal is to create new knowledge and better understanding on the quantum mechanics and sub-nanometer level of how electrons and atoms are organized in solids and near surfaces. In particular, the results lead to new views and explanations on the mechanisms behind the extremely variable properties of new and old materials used in various devices and applications. Research in this field is crucial for all developments in relation with new materials. Scientific frame and methodology:The frame and methodology is given by the experimental possibilities. In the present project angle-resolved photoemission and scanning tunneling microscopy and spectroscopy experiments are done. These experiments allow a very detailed investigation of the “organization” of electrons and atoms at the surface and close to it. However, these experiments require well-defined surfaces of the materials under study and stringent vacuum conditions.
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