Experimental determination of correlations between spontaneously formed vortices in a superconductor

TL;DR

This study visualizes and analyzes the spatial correlations of vortices formed spontaneously in a superconductor during rapid cooling, confirming theoretical predictions and examining the effects of gauge fields.

Contribution

It provides experimental data on vortex correlations in superconductors quenched at high rates, validating the Kibble-Zurek mechanism through direct imaging and simulation comparison.

Findings

Vortex arrays are consistent with Kibble-Zurek predictions.

Correlation functions are unaffected by gauge fields.

Results align with time-dependent Ginzburg-Landau simulations.

Abstract

We have imaged spontaneously created arrays of vortices (magnetic flux quanta), generated in a superconducting film quenched through its transition temperature at rates around $10^9 K/s$. From these images, we calculated the positional correlation functions for two vortices and for 3 vortices. We compared our results with simulations of the time dependent Ginzburg Landau equation in 2D. The results are in agreement with the Kibble-Zurek scenario of spontaneous vortex creation. In addition, the correlation functions are insensitive to the presence of a gauge field.