Nonlinear Driven Response of a Phase-Field Crystal in a Periodic Pinning Potential

Abstract

We study numerically the phase diagram and the response under a driving force of the phase field crystal model for pinned lattice systems introduced recently for both one and two dimensional systems. The model describes the lattice system as a continuous density field in the presence of a periodic pinning potential, allowing for both elastic and plastic deformations of the lattice. We first present results for phase diagrams of the model in the absence of a driving force. The nonlinear response to a driving force on an initially pinned commensurate phase is then studied via overdamped dynamic equations of motion for different values of mismatch and pinning strengths. For large pinning strength the driven depinning transitions are continuous, and the sliding velocity varies with the force from the threshold with power-law exponents in agreement with analytical predictions. Transverse depinning transitions in the moving state are also found in two dimensions. Surprisingly, for sufficiently weak pinning potential we find a discontinuous depinning transition with hysteresis even in one dimension under overdamped dynamics. We also characterize structural changes of the system in some detail close to the depinning transition.

References in corpus (2)

• Phase Diagram and Commensurate-Incommensurate Transitions in the Phase Field Crystal Model with an External Pinning Potential
• Spontaneous Transverse Response and Amplified Switching in Superconductors with Honeycomb Pinning Arrays

Cited by in corpus (3)

• Phase-field-crystal models for condensed matter dynamics on atomic length and diffusive time scales: an overview
• Depinning and heterogeneous dynamics of colloidal crystal layers under shear flow
• Brownian dynamics study of driven partially pinned solid in the presence of square array of pinning centers: Enhanced pinning close to the melting transition