Effect of Electron-Phonon Coupling on Thermal Transport across Metal-Nonmetal Interface - A Second Look

TL;DR

This study uses molecular dynamics simulations to explore how electron-phonon coupling influences thermal conductance at metal-nonmetal interfaces, revealing it can both hinder and enhance heat transfer depending on the coupling strength.

Contribution

It provides a detailed analysis of the dual role of electron-phonon coupling in thermal transport at metal-nonmetal interfaces, a topic not fully understood before.

Findings

E-ph coupling can add thermal resistance.

E-ph interaction can enhance phonon energy transfer.

Total conductance varies with coupling strength.

Abstract

The effect of electron-phonon (e-ph) coupling on thermal transport across metal-nonmetal interfaces is yet to be completely understood. In this paper, we use a series of molecular dynamics (MD) simulations with e-ph coupling effect included by Langevin dynamics to calculate the thermal conductance at a model metal-nonmetal interface. It is found that while e-ph coupling can present additional thermal resistance on top of the phonon-phonon thermal resistance, it can also make the phonon-phonon thermal conductance larger than the pure phonon transport case. This is because the e-ph interaction can disturb the phonon subsystem and enhance the energy communication between different phonon modes inside the metal. This facilitates redistributing phonon energy into modes that can more easily transfer energy across the interfaces. Compared to the pure phonon thermal conduction, the total thermal conductance with e-ph coupling effect can become either smaller or larger depending on the coupling factor. This result helps clarify the role of e-ph coupling in thermal transport across metal-nonmetal interface.