Kinematic vortices and phase slip lines in the dynamics of the resistive state of narrow superconductive thin film channels

Abstract

The resistive state of a superconducting thin film channel (bridge) of intermediate width W(ξ⪡W⪡λeff, ξ is the coherence length and λeff is the effective magnetic penetration depth) - this case is relevant to the nanoscale high-Tc superconductor thin film bridges - is studied by simulations of two-dimensional time-dependent Ginzburg-Landau equations. It is found that in the uniform narrow channel at high dimensionless conductivity Σ the dynamical behavior is due to appearance of the phase slip lines, but at lower Σ vortices appear in the resistive state. In inhomogeneous channels vortices appear at any Σ. We call these vortices kinematic vortices because, unlike the Abrikosov vortices, they can not be treated as quasiparticles. They move with any velocity depending on the current distribution over the bridge (the bridge inhomogeneity). The more uniform the current distribution, the higher the vortex velocity. A kinematic vortex with infinite velocity is a phase slip line.