Intermittently Flowing Rivers of Quantized Magnetic Flux

TL;DR

This paper presents evidence of intermittent, river-like flows of quantized magnetic flux in superconductors, demonstrating complex vortex dynamics including formation, freezing, and reappearance of flux channels around trapped islands.

Contribution

It provides experimental and simulation evidence of dynamic vortex flow patterns, revealing new insights into flux behavior in superconductors.

Findings

Flux rivers form and reappear intermittently

Vortex islands are temporarily trapped and change shape

Flow patterns depend on pinning sites and loading cycles

Abstract

Recent experiments and realistic flux-gradient-driven computer simulations provide evidence of plastic flow of flux lines in a superconductor. The striking videos of the onset of vortex motion vividly illustrate the existence of flowing "rivers" of quantized magnetic flux that intermittently form, freeze, and reappear at different locations in the sample. These rivers flow around "islands" (or domains) of flux lines which are temporarily trapped by the pinning sites. The shape and size of these temporarily frozen islands abruptly change over time with every loading-unloading cycle. Videos of the phenomena are available at: http://www-personal.engin.umich.edu/~nori/ (theory).