Dresden 2006 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 25: Correlated Electrons - Poster Session

TT 25.45: Poster

Mittwoch, 29. März 2006, 14:30–18:30, P1

DMFT/NRG Studies of the Transport Properties of Heavy Fermion Systems — •Claas Grenzebach¹, Frithjof B. Anders^1,2, and Gerd Czycholl¹ — ¹Institut für Theoretische Physik, Universität Bremen — ²Theoretische Physik, Universität des Saarlands, Saarbrücken

Heavy fermion systems (HFS) are described by the periodic Anderson model (PAM), which is mapped onto an effective single impurity Anderson model (SIAM) by dynamical mean field theory (DMFT). The SIAM is treated with the non-perturbative method of numerical renormalization group (NRG). This has the advantage that the correct Kondo scale is obtained. We investigate the (electronic) transport properties and the characteristic low temperature scales of HFS within this DMFT/NRG approach and calculate the temperature dependence of the resistivity and the thermoelectrical power as well as the frequency and temperature dependence of the dynamical conductivity and compare our results with experimental results typical for HFS. An extension of the model and method to take into account substitutional disorder by means of the coherent potential approximation (CPA) is discussed. Furthermore, we compare our results with the corresponding results obtained by using modified perturbation theory (MPT) as impurity solver. The MPT is exact up to second order in the Coulomb correlation U and reproduces the atomic limit (V=0).