The thermal conductance of a two-channel Kondo model

TL;DR

This paper develops a theoretical framework for understanding thermal transport in a two-channel Kondo system, revealing universal behavior of the Lorentz number at low temperatures regardless of the ground state.

Contribution

It introduces a combined analytical and numerical approach to analyze thermal conductance in two-channel Kondo models, exploring both Fermi liquid and non-Fermi liquid regimes.

Findings

Lorentz number reaches universal value at low temperatures

Thermal conductance exhibits characteristic temperature dependence

Fermi liquid and non-Fermi liquid regimes are distinguishable

Abstract

A theory of thermal transport in a two-channel Kondo system, such as the one formed by a small quantum dot coupled to two leads and to a larger dot, is formulated. The interplay of the two screening constants allows an exploration of the Fermi liquid and non-Fermi liquid regimes. By using analytical, as well as numerical renormalization group methods, we study the temperature dependence of the thermal conductance and the Lorentz number. We find that in the low temperature limit, the Lorentz number attains its universal value, irrespective of the nature of the ground state.