Optimal Energy Dissipation in Sliding Friction Simulations

TL;DR

This paper introduces a microscopic, parameter-free dissipation method for molecular dynamics simulations of sliding friction, improving accuracy in Joule heat removal and matching results from standard Langevin schemes.

Contribution

We develop a fully microscopic, non-Markovian dissipation approach that accurately models Joule heat removal in sliding friction simulations, aligning with traditional Langevin methods.

Findings

Exact frictional results closely match Langevin dissipation schemes.

The new dissipation method is parameter-free and variationally determined.

Improves reliability of non-equilibrium molecular dynamics simulations.

Abstract

Non-equilibrium molecular dynamics simulations, of crucial importance in sliding friction, are hampered by arbitrariness and uncertainties in the removal of the frictionally generated Joule heat. Building upon general pre-existing formulation, we implement a fully microscopic dissipation approach which, based on a parameter-free, non-Markovian, stochastic dynamics, absorbs Joule heat equivalently to a semi-infinite solid and harmonic substrate. As a test case, we investigate the stick-slip friction of a slider over a two-dimensional Lennard-Jones solid, comparing our virtually exact frictional results with approximate ones from commonly adopted dissipation schemes. Remarkably, the exact results can be closely reproduced by a standard Langevin dissipation scheme, once its parameters are determined according to a general and self-standing variational procedure.