Nonequilibrium dislocation dynamics and instability of driven vortex lattices in two dimensions

TL;DR

This paper investigates how dislocations in a driven two-dimensional vortex lattice with impurities lead to anisotropic distortions and an instability caused by nonlinear effects, affecting the lattice's structural integrity.

Contribution

It introduces a coarse-grained model incorporating nonlinear dynamics to describe dislocation behavior and instability in nonequilibrium vortex lattices.

Findings

Dislocations cause anisotropic vortex density distortions.

Nonlinear effects lead to screening and proliferation of free dislocations.

Vortex lattice becomes unstable due to dislocation dynamics.

Abstract

We consider dislocations in a vortex lattice that is driven in a two-dimensional superconductor with random impurities. The structure and dynamics of dislocations is studied in this genuine nonequilibrium situation on the basis of a coarse-grained equation of motion for the displacement field. The presence of dislocations leads to a characteristic anisotropic distortion of the vortex density that is controlled by a Kardar-Parisi-Zhang nonlinearity in the coarse-grained equation of motion. This nonlinearity also implies a screening of the interaction between dislocations and thereby an instability of the vortex lattice to the proliferation of free dislocations.