Electronic versus Phononic Friction of Xenon on Silver

TL;DR

This study uses molecular dynamics simulations to compare electronic and phononic contributions to friction of xenon monolayers sliding on silver surfaces, revealing both channels are similarly significant.

Contribution

It provides a detailed analysis of electronic versus phononic friction mechanisms in xenon-silver systems, highlighting their comparable roles.

Findings

Electronic and phononic dissipation are of similar importance.

Phonon friction varies rapidly with coverage.

Electronic friction remains roughly coverage-independent.

Abstract

Molecular dynamics simulations of a Xe monolayer sliding on Ag(001) and Ag(111) are carried out in order to ascertain the microscopic origin of friction. For several values of the electronic contribution to the friction of individual Xe atoms, the intra-overlayer phonon dissipation is calculated as a function of the corrugation amplitude of the substrate potential, which is a pertinent parameter to consider. Within the accuracy of the numerical results and the uncertainty with which the values of the relevant parameters are known at present, we conclude that electronic and phononic dissipation channels are of similar importance. While phonon friction gives rise to the rapid variation with coverage, the electronic friction provides a roughly coverage-independent contribution to the overall sliding friction.