DPG Phi
Verhandlungen
Verhandlungen
DPG

Berlin 2015 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

TT: Fachverband Tiefe Temperaturen

TT 112: Correlated Electrons: (General) Theory 3

TT 112.7: Talk

Friday, March 20, 2015, 11:15–11:30, H 3010

First order character and observable signatures of topological quantum phase transitions — •Adriano Amaricci1, Jan Budich2,3, Bjoern Trauzettel4, Massimo Capone1, and Giorgio Sangiovanni41Democritos National Simulation Center, Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali (IOM) and Scuola Internazionale Superiore di Studi Avanzati (SISSA), Via Bonomea 265, 34136 Trieste, Italy — 2Institute for Theoretical Physics, University of Innsbruck, 6020 Innsbruck, Austria — 3Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, 6020 Innsbruck, Austria — 4Institut fur Theoretische Physik und Astrophysik, Universitat Wuerzburg, Am Hubland, D-97074 Wuerzburg, German

Topological quantum phase transitions are characterised by changes in global topological invariants beyond the paradigm of spontaneous symmetry breaking. For non-interacting electrons, such transitions are continuous and always accompanied by a gap-closing in the energy spectrum. Here, we demonstrate that sufficiently strong electron-electron interaction can fundamentally change the situation: we discover a topological quantum phase transition of first order character in the genuine thermodynamic sense, that occurs without gap closing. Our theoretical study reveals the existence of a quantum critical endpoint associated with an orbital instability on the transition line between a 2D topological insulator and a trivial band insulator. Remarkably, this phenomenon entails unambiguous signatures associated to the orbital occupations that can be detected experimentally.

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 2015 > Berlin