Berlin 2018 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 94: Correlated Electrons: Other Theoretical Topics
TT 94.3: Vortrag
Donnerstag, 15. März 2018, 15:30–15:45, H 3010
Breakdown of Traditional Many-Body Theories for Correlated Electrons — •Thomas Schäfer1,2,3, Olle Gunnarsson4, Georg Rohringer5, Giorgio Sangiovanni6, and Alessandro Toschi1 — 1TU Wien, Austria — 2Collège de France, Paris, France — 3CPHT École Polytechnique, Palaiseau, France — 4MPI Stuttgart, Germany — 5Russian Quantum Center, Moscow, Russia — 6Uni Würzburg, Germany
Starting from the (Hubbard) model of an atom, we demonstrate that the uniqueness of the mapping from the interacting to the noninteracting Green function, G→ G0, is strongly violated, by providing numerous explicit examples of different G0 leading to the same physical G. We argue that there are indeed infinitely many such G0, with numerous crossings with the physical solution. We show that this rich functional structure is directly related to the divergence of certain classes of (irreducible vertex) diagrams, with important consequences for traditional many-body physics based on diagrammatic expansions. Physically, we ascribe the onset of these highly nonperturbative manifestations to the progressive suppression of the charge susceptibility induced by the formation of local magnetic moments and/or resonating valence bond (RVB) states in strongly correlated electron systems.