Defects, order, and hysteresis in driven charge-density waves

TL;DR

This paper models driven 2D charge-density waves in disordered media, revealing defect dynamics, switching phenomena, and hysteresis, aligning with recent experimental observations.

Contribution

It introduces a modified Swift-Hohenberg model capturing amplitude and phase fluctuations, providing new insights into defect behavior and hysteresis in driven charge-density waves.

Findings

Defect density peaks then decreases with increased driving force.

Switching phenomena due to dislocation channels are observed.

Results qualitatively match recent experimental data.

Abstract

We model driven two-dimensional charge-density waves in random media via a modified Swift-Hohenberg equation, which includes both amplitude and phase fluctuations of the condensate. As the driving force is increased, we find that the defect density first increases and then decreases. Furthermore, we find switching phenomena, due to the formation of channels of dislocations. These results are in qualitative accord with recent dynamical x-ray scattering experiments by Ringlandet al. and transport experiments by Lemay et al.