On ultrafast magnetic flux dendrite propagation into thin superconducting films

TL;DR

This paper introduces a new theoretical model for the rapid propagation of magnetic flux dendrites into thin superconducting films, validated by experimental data, revealing an inverse relationship between dendrite velocity and film thickness.

Contribution

The paper presents a novel theoretical approach to describe flux dendrite velocity in thin superconducting films, supported by experimental validation and identifying two propagation regimes.

Findings

Dendrite velocity is inversely proportional to film thickness.

Two propagation regimes are identified: a fast initial and a slow stage.

Theoretical predictions agree well with experimental measurements.

Abstract

We suggest a new theoretical approach describing the velocity of magnetic flux dendrite penetration into thin superconducting films. The key assumptions for this approach are based upon experimental observations. We treat a dendrite tip motion as a propagating flux jump instability. Two different regimes of dendrite propagation are found. A fast initial stage is followed by a slow stage, which sets in as soon as a dendrite enters into the vortex-free region. We find that the dendrite velocity is inversely proportional to the sample thickness. The theoretical results and experimental data obtained by a magneto-optic pump-probe technique are compared and excellent agreement between the calculations and measurements is found.