Transport properties of clean and disordered Josephson junction arrays

TL;DR

This paper studies how quantum fluctuations and weak disorder affect vortex movement and electrical transport in two-dimensional superconducting Josephson junction arrays, highlighting a quantum-to-classical crossover and disorder-induced critical current reduction.

Contribution

It provides a detailed analysis of the quantum regime in vortex dynamics and quantifies the impact of weak disorder on critical current in Josephson junction arrays.

Findings

Quantum fluctuations dominate vortex creep below a certain temperature.

Weak disorder reduces the critical current compared to clean systems.

A quantum correction to the classical current-voltage relation is derived.

Abstract

We investigate the influence of quantum fluctuations and weak disorder on the vortex dynamics in a two-dimensional superconducting Berezinskii-Kosterlitz-Thouless system. The temperature below which quantum fluctuations dominate the vortex creep is determined, and the transport in this quantum regime is described. The crossover from quantum to classical regime is discussed and the quantum correction to the classical current-voltage relation is determined. It is found that weak disorder can effectively reduce the critical current as compared to that in the clean system.