Shear Banding and Spatiotemporal Oscillations in Vortex Matter in Nanostructured Superconductors

TL;DR

This paper investigates vortex shear banding and oscillations in nanostructured superconductors with a modified pinning array, revealing complex dynamical phenomena through simulations that could be observed experimentally.

Contribution

It introduces a novel pinning array geometry that exhibits shear banding and oscillatory vortex motion, expanding understanding of vortex dynamics in nanostructured superconductors.

Findings

Shear banding occurs with a single row of removed pinning sites.

Oscillations in vortex velocity profiles are observed near depinning.

Simulations suggest these effects influence transport properties.

Abstract

We propose a simple nanostructured pinning array geometry where a rich variety of complex vortex shear banding phenomena can be realized. A single row of pinning sites is removed from a square pinning array. Shear banding effects arise when vortex motion in the pin-free channel nucleates motion of vortices in the surrounding pinned regions, creating discrete steps in the vortex velocity profile away from the channel. Near the global depinning transition, the width of the band of moving vortices undergoes oscillations or fluctuations that can span the entire system. We use simulations to show that these effects should be observable in the transport properties of the system. Similar large oscillations and shear banding effects are known to occur for sheared complex fluids in which different dynamical phases coexist.