Electronic thermal conductivity of disordered metals

TL;DR

This paper investigates how electron interactions and environmental effects influence thermal conductivity in disordered metals, revealing mechanisms that violate the Wiedemann-Franz law and significantly enhance the Lorenz ratio.

Contribution

It introduces a theory distinguishing two interaction mechanisms affecting thermal transport and predicts Lorenz ratio enhancement due to environmental impedance effects.

Findings

Interaction affects thermal transport via quantum interference and energy exchange.

Violation of Wiedemann-Franz law in the presence of large environmental impedance.

Predicted strong enhancement of Lorenz ratio beyond standard law.

Abstract

We calculate the thermal conductivity of interacting electrons in disordered metals. In our analysis we point out that the interaction affects thermal transport through two distinct mechanims, associated with quantum interference corrections and energy exchange of the quasi particles with the electromagnetic environment, respectively. The latter is seen to lead to a violation of the Wiedemann-Franz law. Our theory predicts a strong enhancement of the Lorenz ratio $\kappa /\sigma T$ over the value which is predicted by the Wiedemann-Franz law, when the electrons encounter a large environmental impedance.