Current--Voltage Characteristics of Two--Dimensional Vortex Glass Models

TL;DR

This study uses Monte Carlo simulations to analyze the current-voltage behavior of two-dimensional vortex glass models, revealing a zero-temperature transition and exponential decay of resistance, with results aligning with experimental data.

Contribution

It provides new insights into vortex glass behavior at low temperatures, especially the exponential vanishing of resistance and the T^3 scaling of the nonlinear current scale.

Findings

Zero-temperature transition confirmed

Exponential decay of linear resistance as T→0

Nonlinear current scale varies as T^3

Abstract

We have performed Monte Carlo simulations to determine current--voltage characteristics of two different vortex glass models in two dimensions. The results confirm the conclusions of earlier studies that there is a transition at $T=0$. In addition we find that, as $T\to 0$, the linear resistance vanishes exponentially, and the current scale, $J_{nl}$, where non-linearities appear in the $I$--$V$ characteristics varies roughly as $T^3$, quite different from the predictions of conventional flux creep theory, $J_{nl} \sim T$. The results for the two models agree quite well with each other, and also agree fairly well with recent experiments on very thin films of YBCO.