Ultra-fast Kinematic Vortices in Mesoscopic Superconductors: The Effect of the Self-Field

TL;DR

This study uses generalized time-dependent Ginzburg-Landau equations to analyze how magnetic self-fields induce rapid kinematic vortex-antivortex pairs in mesoscopic superconductors, revealing intrinsic mechanisms behind resistive states.

Contribution

It demonstrates that inhomogeneous current distributions and vortex pairs can emerge without material inhomogeneity or normal contacts, advancing understanding of vortex dynamics in superconductors.

Findings

Vortex-antivortex pairs form without material inhomogeneity.

Vortex velocity and annihilation rates explain resistive behavior.

Peak current-resistance correlates with vortex pair formation.

Abstract

Within the framework of the generalized time-dependent Ginzburg-Landau equations, we studied the influence of the magnetic self-field induced by the currents inside a superconducting sample driven by an applied transport current. The numerical simulations of the resistive state of the system show that neither material inhomogeneity nor a normal contact smaller than the sample width are required to produce an inhomogeneous current distribution inside the sample, which leads to the emergence of a kinematic vortex-antivortex pair (vortex street) solution. Further, we discuss the behaviors of the kinematic vortex velocity, the annihilation rates of the supercurrent, and the superconducting order parameters alongside the vortex street solution. We prove that these two latter points explain the characteristics of the resistive state of the system. They are the fundamental basis to describe the peak of the current-resistance characteristic curve and the location where the vortex-antivortex pair is formed.