Hamburg 2001 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 23: Korrelierte Elektronensysteme Theorie III

TT 23.1: Vortrag

Donnerstag, 29. März 2001, 14:30–14:45, H

Dynamical quantities within the CTMA — •Stefan Kirchner, Johann Kroha, and Peter Wölfle — Institut fuer Theorie der Kondensierten Materie, Universität Karlsruhe

Recently we have proposed a novel diagrammatic approximation scheme for the SU(N)×SU(M) Anderson impurity models (SIAM) within an auxiliary particle representation [ J. Kroha, P. Wölfle, T.A. Costi; Phys. Rev. Lett. 79, 261 (1997)]. These models exhibit Fermi-liquid (FL), (M=1) or non-Fermi-liquid (NFL), (N ≥2, M≥2) behavior, depending on their symmetry. Detailed studies of the auxiliary particle threshold exponents which characterize the FL vs. NFL dynamics of such models in a slave particle representation showed that this approximation, the CTMA is able to correctly describe the low temperature behavior of the one- and multi-channel SIAM. We here present results for the physical impurity spectral function which imply that the approximation indeed captures the correct FL and NFL behavior of the models. Results for the spin susceptibility and the conductivity will also be presented.