Regensburg 2007 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 5: Correlated Electrons - (General) Theory
TT 5.3: Vortrag
Montag, 26. März 2007, 14:45–15:00, H18
Kinks in the dispersion of strongly correlated electrons — •Marcus Kollar1, Krzysztof Byczuk1,2, Karsten Held3, Yi-Feng Yang3, Igor Nekrasov4, Thomas Pruschke5, and Dieter Vollhardt1 — 1Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute for Physics, University of Augsburg — 2Institute of Theoretical Physics, Warsaw University — 3Max-Planck Institute for Solid State Research, Stuttgart — 4Institute for Electrophysics, Russian Academy of Sciences, Ekaterinburg — 5Institute for Theoretical Physics, University of Göttingen
The properties of condensed matter are determined by single-particle and collective excitations and their interactions. The coupling of two excitations may lead to abrupt changes (kinks) in the slope of the dispersion. Such kinks thus carry important information about interactions in a many-body system are of great interest, e.g., in the high-temperature superconductors. We report a novel, purely electronic mechanism yielding kinks in the electron dispersions [1]. It applies to strongly correlated metals whose spectral function shows well separated Hubbard subbands and central peak as, for example, in transition metal-oxides. The position of the kinks and the energy range of validity of Fermi-liquid (FL) theory is determined solely by the FL renormalization factor and the bare, uncorrelated band structure. ARPES experiments at binding energies outside the FL regime can thus provide new, previously unexpected information about strongly correlated electronic systems.
[1] K. Byczuk et al., Preprint cond-mat/0609594.