Transport Coefficients of the Anderson Model

TL;DR

This paper extends Wilson's numerical renormalization group method to accurately compute the transport coefficients of the Anderson model across all temperature regimes, providing insights into strongly correlated electron systems.

Contribution

The authors develop an extension of NRG to calculate spectral densities and transport coefficients of the Anderson model at all temperatures, including the crossover and low-temperature regimes.

Findings

Accurate calculation of transport coefficients across all temperature regimes.

Validation of Fermi liquid relations for resistivity and thermopower.

Provides a new approach for studying strongly correlated electrons in high dimensions.

Abstract

The transport coefficients of the Anderson model require knowledge of both the temperature and frequency dependence of the single--particle spectral densities and consequently have proven difficult quantities to calculate. Here we show how these quantities can be calculated via an extension of Wilson's numerical renormalization group method. Accurate results are obtained in all parameter regimes and for the full range of temperatures of interest ranging from the high temperature perturbative regime $T>>T_{K}$, through the cross--over region $T\approx T_{K}$, and into the low temperature strong coupling regime $T<<T_{K}$. The Fermi liquid relations for the $T^2$ coefficient of the resistivity and the linear coefficient of the thermopower are satisfied to a high degree of accuracy. The techniques used here provide a new highly accurate approach to strongly correlated electrons in high dimensions.