Nonlinear sliding friction of adsorbed overlayers on disordered substrates

TL;DR

This paper investigates how adsorbed monolayers respond to driving forces on disordered substrates, revealing that depinning transitions persist under weak disorder but become smeared with strong disorder, explaining recent experimental data.

Contribution

It provides a detailed simulation study of nonlinear sliding friction in disordered systems, highlighting the effects of disorder strength on depinning transitions.

Findings

Depinning transitions persist with weak disorder

Transitions become smeared with strong disorder

Results explain recent Kr film experiments

Abstract

We study the response of an adsorbed monolayer on a disordered substrate under a driving force using Brownian molecular-dynamics simulation. We find that the sharp longitudinal and transverse depinning transitions with hysteresis still persist in the presence of weak disorder. However, the transitions are smeared out in the strong disorder limit. The theoretical results here provide a natural explanation for the recent data for the depinning transition of Kr films on gold substrate.