Nonequilibrium steady states of driven magnetic flux lines in disordered type-II superconductors

TL;DR

This paper explores the behavior of magnetic flux lines in disordered type-II superconductors under various driving conditions, revealing complex steady-state phenomena through simulations and multiple observable analyses.

Contribution

It introduces a detailed simulation study of flux line dynamics in disordered superconductors, highlighting the impact of defect types on steady-state properties.

Findings

Distinct steady-state behaviors for point and columnar defects

Complex vortex structures and fluctuations observed

Variety of transport phenomena identified

Abstract

We investigate driven magnetic flux lines in layered type-II superconductors subject to various configurations of strong point or columnar pinning centers by means of a three-dimensional elastic line model and Metropolis Monte Carlo simulations. We characterize the resulting nonequilibrium steady states by means of the force-velocity / current-voltage curve, static structure factor, mean vortex radius of gyration, number of double-kink and half-loop excitations, and velocity / voltage noise spectrum. We compare the results for the above observables for randomly distributed point and columnar defects, and demonstrate that the three-dimensional flux line structures and their fluctuations lead to a remarkable variety of complex phenomena in the steady-state transport properties of bulk superconductors.