Enhancement of thermal transport in the degenerate periodic Anderson model

TL;DR

This paper investigates how thermal transport properties are enhanced in the degenerate periodic Anderson model at low temperatures, revealing implications for thermoelectric efficiency and electrical resistance anomalies in certain intermetallic compounds.

Contribution

It provides a detailed analysis of low-temperature transport coefficients using dynamical mean-field theory, highlighting the impact of quasiparticle damping on thermal and electrical properties.

Findings

Reduced Lorenz number in Wiedemann-Franz law due to quasiparticle damping

Potential enhancement of thermoelectric figure-of-merit at low temperatures

Explanation of resistance anomalies in Ce and Yb intermetallics under pressure

Abstract

The low-temperature transport coefficients of the degenerate periodic SU(N) Anderson model are calculated in the limit of infinite correlation between {\it f} electrons, within the framework of dynamical mean-field theory. We establish the Fermi liquid (FL) laws in the clean limit, taking into account the quasiparticle damping. The latter yields a reduced value of the Lorenz number in the Wiedemann-Franz law. Our results indicate that the renormalization of the thermal conductivity and of the Seebeck coefficient can lead to a substantial enhancement of the electronic thermoelectric figure-of-merit at low temperature. Using the FL laws we discuss the low-temperature anomalies that show up in the electrical resistance of the intermetallic compounds with Cerium and Ytterbium ions, when studied as a function of pressure. Our calculations explain the sharp maximum of the coefficient of the $T^2$-term of the electrical resistance and the rapid variation of residual resistance found in a number of Ce and Yb intermetallics at some critical pressure.