Vortex dynamics in disordered type-II superconductors

TL;DR

This paper develops a field theoretical approach to study vortex dynamics in disordered type-II superconductors, deriving equations for averaged quantities and predicting experimental signatures of vortex lattice melting.

Contribution

It introduces a self-consistent field theoretical method and a novel experimental proposal to observe vortex lattice melting through interference steps in I-V characteristics.

Findings

Derived self-consistent equations for vortex dynamics in disordered environments.

Calculated I-V characteristics in the flux flow regime.

Proposed an experiment to detect vortex lattice melting via interference steps.

Abstract

A field theoretical method is developed which permits us to study the dynamics of vortices in disordered environments. In particular, we obtain a self-consistent system of equations for disorder averaged quantities. Making use of a Hartree-type approximation, we calculate the current-voltage (I-V) characteristics in the flux flow regime. In order to probe incipient melting of the vortex lattice we propose an experiment where interference steps in the I-V characteristics are observed, which arise when a small ac field is superimposed on the constant voltage.