Macroturbulent Instability of the Flux Line Lattice in Anisotropic Superconductors

TL;DR

This paper develops a theoretical model explaining how anisotropy in superconductors causes macroturbulent instability in the vortex lattice during magnetization reversal, leading to flow turbulization.

Contribution

It introduces a new theory linking anisotropic current properties to vortex lattice instability in superconductors, supported by analytical and numerical analysis.

Findings

Instability can occur even with weak anisotropy.

Derived dispersion relation for instability growth rate.

Identified tangential discontinuity as the instability trigger.

Abstract

A theory of the macroturbulent instability in the system containing vortices of opposite directions (vortices and antivortices) in hard superconductors is proposed. The origin of the instability is connected with the anisotropy of the current capability in the sample plane. The anisotropy results in the appearance of tangential discontinuity of the hydrodynamic velocity of vortex and antivortex motion near the front of magnetization reversal. As is known from the classical hydrodynamics of viscous fluids, this leads to the turbulization of flow. The examination is performed on the basis of the anisotropic power-law current-voltage characteristics. The dispersion equation for the dependence of the instability increment on the wave number of perturbation is obtained, solved, and analyzed analytically and numerically. It is shown that the instability can be observed even at relatively weak anisotropy.