Direct Numerical Confirmation of Pinning Induced Sign Change in Superconducting Hall Effect in Type-II Superconductors

TL;DR

This study uses numerical simulations to confirm that vortex pinning causes a sign change in the Hall effect in disordered type-II superconductors, revealing a universal behavior.

Contribution

It provides the first direct numerical evidence linking vortex pinning to Hall sign reversal in type-II superconductors.

Findings

Hall voltage changes sign in plastic flow phase

Vortex drift is influenced by pinned vortices' circular current

Hall sign change is a universal feature in disordered superconductors

Abstract

Using the time-dependent Ginzburg-Landau equation with the complex relaxation time and the Maxwell equation, we systematically examine transverse motion of vortex dynamics in the presence of pinning disorders. Consequently, in a plastic flow phase in which moving and pinned vortices coexist, we find that the Hall voltage generally changes its sign. The origin of the sign change is ascribed to a fact that moving vortices are strongly drifted by circular current of pinned vortices and the enforced transverse moving direction becomes opposite to that by transport current. This suggests that the Hall sign change is a behavior common in all disordered type-II superconductors.