Dendritic flux avalanches in rectangular superconducting films -- numerical simulations

TL;DR

This paper uses numerical simulations to study dendritic flux avalanches in rectangular superconducting films, confirming theoretical predictions at low temperatures and revealing disorder-driven behavior at higher temperatures.

Contribution

It provides the first numerical validation of the predicted nucleation sites of flux avalanches and explores the influence of temperature and disorder on their initial occurrence.

Findings

Avalanches occur at the middle of the long edges at low temperatures.

At higher temperatures, disorder influences the avalanche location.

Simulation results agree with linear stability analysis predictions at low T.

Abstract

Dendritic flux avalanches is a frequently encountered instability in the vortex matter of type II superconducting films at low temperatures. Previously, linear stability analysis has shown that such avalanches should be nucleated where the flux penetration is deepest. To check this prediction we do numerical simulations on a superconducting rectangle. We find that at low substrate temperature the first avalanches appear exactly in the middle of the long edges, in agreement with the predictions. At higher substrate temperature, where there are no clear predictions from the theory, we find that the location of the first avalanche is decided by fluctuations due to the randomly distributed disorder.