Critical currents at the Bragg glass to vortex glass transition

TL;DR

This study uses simulations of a frustrated anisotropic 3D XY model with point disorder to analyze the transport properties and critical current behavior at the first-order transition from the Bragg glass to the vortex glass phase in superconductors.

Contribution

It demonstrates how the critical currents change discontinuously at the BG-VG transition, confirming the first-order nature of the phase change through simulation results.

Findings

In-plane critical current sharply increases at the transition.

c-axis critical current exhibits a discontinuous drop.

Results support the first-order transition hypothesis.

Abstract

We present simulations of the transport properties of superconductors at the transition from the Bragg glass (BG) to the vortex glass (VG) phase. We study the frustrated anisotropic 3D XY model with point disorder, which has been shown to have a first order transition as a function of the intensity of disorder. We add an external current to the model and we obtain current-voltage curves as a function of disorder at a low temperature. We find that the in-plane critical current has a steep increase at the BG-VG transition, while the c-axis critical current has a discontinous jump down, this later result in agreement with the first-order character of the transition.