Dynamical transitions and sliding friction of the phase-field-crystal model with pinning

TL;DR

This paper investigates the nonlinear sliding friction and dynamical transitions in a phase-field-crystal model with pinning, incorporating thermal fluctuations and inertia, revealing hysteresis and melting/freezing phenomena similar to molecular dynamics results.

Contribution

It introduces a stochastic dynamical framework for the PFC model with pinning, thermal fluctuations, and inertia, and explores its nonlinear response and hysteresis behavior.

Findings

Velocity hysteresis observed at low temperatures.

Dynamical melting and freezing transitions identified.

Model reproduces features similar to molecular dynamics simulations.

Abstract

We study the nonlinear driven response and sliding friction behavior of the phase-field-crystal (PFC) model with pinning including both thermal fluctuations and inertial effects. The model provides a continuous description of adsorbed layers on a substrate under the action of an external driving force at finite temperatures, allowing for both elastic and plastic deformations. We derive general stochastic dynamical equations for the particle and momentum densities including both thermal fluctuations and inertial effects. The resulting coupled equations for the PFC model are studied numerically. At sufficiently low temperatures we find that the velocity response of an initially pinned commensurate layer shows hysteresis with dynamical melting and freezing transitions for increasing and decreasing applied forces at different critical values. The main features of the nonlinear response in the PFC model are similar to the results obtained previously with molecular dynamics simulations of particle models for adsorbed layers.