Monte Carlo calculation of the current-voltage characteristics of a two dimensional lattice Coulomb gas

TL;DR

This paper uses Monte Carlo simulations to analyze the nonlinear current-voltage behavior of a 2D lattice Coulomb gas, providing insights that align with experimental observations in superconducting thin films.

Contribution

It introduces three methods to determine the power-law exponent of the nonlinear I-V characteristic, combining equilibrium and non-equilibrium simulations.

Findings

Good agreement between different determination methods.

Results closely match experimental data for superconducting thin films.

Validated the power-law behavior of the Coulomb gas model.

Abstract

We have studied the nonlinear current-voltage characteristic of a two dimensional lattice Coulomb gas by Monte Carlo simulation. We present three different determinations of the power-law exponent $a(T)$ of the nonlinear current-voltage characteristic, $V \sim I^{a(T)+1}$. The determinations rely on both equilibrium and non-equilibrium simulations. We find good agreement between the different determinations, and our results also agree closely with experimental results for Hg-Xe thin film superconductors and for certain single crystal thin-film high temperature superconductors.