Thermal transport across metal-insulator interface via electron-phonon interaction

TL;DR

This paper investigates thermal transport at metal-insulator interfaces via electron-phonon interactions, revealing nonmonotonic conductance behavior and thermal rectification effects influenced by temperature and coupling strength.

Contribution

It introduces a nonequilibrium Green's function approach to analyze electron-phonon mediated thermal transport and rectification at metal-insulator interfaces.

Findings

Thermal conductance exhibits nonmonotonic dependence on temperature and coupling strength.

Significant thermal rectification effect observed, reversible with temperature and coupling changes.

Electron-phonon interaction dominates thermal transport when phonon-phonon coupling is weak.

Abstract

The thermal transport across metal-insulator interface can be characterized by electron-phonon interaction through which an electron lead is coupled to a phonon lead if phonon-phonon coupling at the interface is very weak. We investigate the thermal conductance and rectification flowing between the electron part and the phonon part using nonequilibrium Green's function method. It is found that the thermal conductance has a nonmonotonic behavior as a function of average temperature or the coupling strength between the phonon leads in the metal part and the insulator one. The metal-insulator interface shows evident thermal rectification effect, which can reverse with changing of average temperature or the electron-phonon coupling.