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TT: Tiefe Temperaturen

TT 16: Korrelierte Elektronen: Quantenstörstellen, Kondo-Physik

TT 16.8: Talk

Tuesday, March 9, 2004, 18:30–18:45, H19

Exact ground states of Anderson models with assisted hopping — •Marcus Kollar and Florian Schütz — Institut für Theoretische Physik, Universität Frankfurt, Robert-Mayer-Str. 8, 60054 Frankfurt/Main

Due to the Coulomb interaction the hopping amplitude for an electron into and out of a quantum dot depends on the presence of an opposite-spin electron in the dot, leading to a description in terms of an Anderson impurity model with assisted hopping [1]. Here we show that the application of a local correlator to an uncorrelated state yields the exact ground state for certain parametrizations of this model. We discuss possible valence regimes and calculate the impurity spectral function using a set of variational excited states.

[1] F. Guinea, Phys. Rev. B 67, 195104 (2003).