Tearing transition and plastic flow in superconducting thin films

TL;DR

This paper investigates the transition from rigid to plastic vortex flow in superconducting thin films using numerical simulations, revealing sharp resistance jumps and dislocation dynamics in vortex arrays.

Contribution

It introduces a detailed analysis of tearing and plastic flow transitions in vortex arrays within superconducting disks, highlighting dislocation nucleation and glide mechanisms.

Findings

Resistance exhibits sharp jumps at threshold currents.

Dislocation pairs nucleate and unbind, causing tearing transition.

Plastic flow involves dislocation glide along grain boundaries.

Abstract

A new class of artificial atoms, such as synthetic nanocrystals or vortices in superconductors, naturally self-assemble into ordered arrays. This property makes them applicable to the design of novel solids, and devices whose properties often depend on the response of such assemblies to the action of external forces. Here we study the transport properties of a vortex array in the Corbino disk geometry by numerical simulations. In response to an injected current in the superconductor, the global resistance associated to vortex motion exhibits sharp jumps at two threshold current values. The first corresponds to a tearing transition from rigid rotation to plastic flow, due to the reiterative nucleation around the disk center of neutral dislocation pairs that unbind and glide across the entire disk. After the second jump, we observe a smoother plastic phase proceeding from the coherent glide of a larger number of dislocations arranged into radial grain boundaries.