Influence of band occupation on electron-phonon coupling in gold

TL;DR

This study examines how nonequilibrium electron distributions in gold influence electron-phonon coupling, revealing significant effects that challenge the traditional reliance on electron temperature as the sole predictor.

Contribution

It demonstrates the impact of nonequilibrium electron occupations on the electron-phonon coupling parameter in gold, highlighting a need to consider nonequilibrium effects beyond electron temperature.

Findings

Large influence of nonequilibrium distributions on coupling parameter

Electron temperature alone is insufficient to predict coupling

Challenging conventional models of electron-phonon interactions

Abstract

Electron-phonon coupling is a fundamental process that governs the energy relaxation dynamics of solids excited by ultrafast laser pulses. It has been found to strongly depend on electron temperature as well as on nonequilibrium effects. Recently, the effect of occupational nonequilibrium in noble metals, which outlasts the fully kinetic stage, has come into increased focus. In this work, we investigate the influence of nonequilibrium density distributions in gold on the electron-phonon coupling. We find a large effect on the coupling parameter which describes the energy exchange between the two subsystems. Our results challenge the conventional view that electron temperature alone is a sufficient predictor of electron-phonon coupling.