Anti-Poiseuille Flow: Increased Vortex Velocity at Superconductor Edges

TL;DR

This study reveals a novel vortex flow pattern in superconductors where vortices near edges move faster than those in the interior, contrary to classical fluid dynamics, with implications for experimental observation.

Contribution

The paper introduces the phenomenon of increased vortex velocity at superconductor edges and describes the complex vortex dynamics under varying currents using Ginzburg Landau equations.

Findings

Vortex channels form with edge vortices moving faster.

Stick-slip vortex motion occurs at intermediate currents.

Edge vortex velocity exceeds interior vortex velocity.

Abstract

Using the time-dependent Ginzburg Landau equations we study vortex motion driven by an applied current in two dimensional superconductors in the presence of a physical boundary. At smaller sourced currents the vortex lattice moves as a whole, with each vortex moving at the same velocity. At larger sourced current, vortex motion is organized into channels, with vortices in channels nearer to the sample edges moving faster than those farther away from sample edges, opposite to the Poiseuille flow of basic hydrodynamics where the velocity is lowest at the boundaries. At intermediate currents, a stick-slip motion of the vortex lattice occurs in which vortices in the channel at the boundary break free from the Abrikosov lattice, accelerate, move past their neighbors and then slow down and reattach to the vortex lattice at which point the stick-slip process starts over. These effects could be observed experimentally, e.g. using fast scanning microscopy techniques.