Optimal Energy Dissipation in Sliding Friction Simulations

Non-equilibrium molecular dynamics simula- tions, of crucial importance in sliding friction, are ham- pered by arbitrariness and uncertainties in the removal of the frictionally generated Joule heat. Building upon general pre-existing formulation, we implement a fully micro- scopic 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.