Dynamics of disordered vortex matter in type II superconductors

TL;DR

This paper models the complex dynamics of vortex matter in type II superconductors beyond linear response, incorporating disorder and thermal fluctuations to predict critical currents and phase boundaries, aligning with experimental observations.

Contribution

It introduces a theoretical framework using the time-dependent Ginzburg-Landau equation with lowest Landau level approximation, including disorder and thermal effects, to analyze vortex dynamics.

Findings

Determines critical current Jc(B,T) as a function of magnetic field and temperature.

Identifies a phase boundary between flux flow and vortex glass regimes.

Predicts non-Ohmic I-V characteristics consistent with experiments.

Abstract

Dynamics of homogeneous moving vortex matter is considered beyond the linear response. The framework is the time dependent Ginzburg - Landau equation within the lowest Landau level approximation. Both disorder and thermal fluctuations are included using the Martin-Siggia-Rose formalism. We determine the critical current as function of magnetic field and temperature Jc(B,T). The surface in the J-B-T space defined by the function separates between the dissipative moving vortex matter regime(flux flow)and an amorphous vortex "glass". Both the thermal depinning and the depinning by a driving force are taken into account. The static irreversibility line, determined by Jc(B,T)=0 is compared to experiments in layered HTSC, and is consistent with the one obtained using the replica approach. The non-Ohmic I-V curve (in the depinned phase) is obtained and compared with experiment in layered superconductors and thin films.