Dresden 2011 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 9: CE: (General) Theory 1

TT 9.6: Vortrag

Montag, 14. März 2011, 15:30–15:45, HSZ 201

Spectra and kinks in the electronic dispersion of charge-transfer systems — •Markus Greger, Marcus Kollar, and Dieter Vollhardt — Theoretische Physik III, Zentrum für elektronische Korrelationen und Magnetismus, Universität Augsburg

We investigate kinks in the effective dispersion of correlated multi-band systems, concentrating on the perovskite geometry. Previously it was shown that the one-band Hubbard model exhibits kinks due to an entirely electronic mechanism [1], which is different from conventional mechanisms such as the coupling between electrons and phonons or other bosonic modes. Here we demonstrate the applicability of this mechanism in the case of the Emery model (two/three-band Hubbard model) for hole-doped cuprate compounds. We solve these multi-band models within dynamical mean-field theory using the numerical renormalization group (NRG), which is ideally suited to resolve spectral features at comparably low energy, including kinks. We discuss in detail the construction of the effective impurity Hamiltonian and the corresponding Wilson chains within the NRG procedure for such multi-band models.
K. Byczuk, M. Kollar, K. Held, Y.-F. Yang, I. A. Nekrasov, Th. Pruschke and D. Vollhardt, Nature Physics 3, 168 (2007).