Pinning and Depinning of the Bragg Glass in a Point Disordered Model Superconductor

TL;DR

This study uses simulations to explore how a Bragg glass in a disordered superconductor responds to pinning and depinning under current and temperature, revealing a critical current and a collapse of data behavior.

Contribution

It introduces a detailed simulation analysis of the pinning and depinning mechanisms of the Bragg glass in a disordered superconductor model, highlighting the critical current and data collapse phenomena.

Findings

Identification of a critical current I_c separating creep and flow regimes.

Observation of voltage versus current behavior near I_c.

Data collapse when plotting voltage against T*I at fixed disorder.

Abstract

The three-dimensional frustrated anisotropic XY model with point disorder is studied with both Monte Carlo simulations and resistively-shunted-junction dynamics to model the dynamics of a type-II superconductor with quenched point pinning in a magnetic field and a weak applied current. Both the collective pinning and the depinning of the Bragg glass is examined. We find a critical current I_c that separates a creep region with unmeasurable low voltage from a region with a voltage V \sim I-I_c, and also identify the mechanism behind this behavior. It is further found to be possible to collapse the data obtained at a fixed disorder strength by plotting the voltage versus TI, where T is the temperature, though the reason for this behavior is unclear.