Scaling Laws for Fluxon Formation in Annular Josephson Tunnel Junctions

TL;DR

This paper experimentally investigates the Zurek-Kibble scaling law for defect formation in Josephson Tunnel Junctions, confirming the predicted scaling exponent and normalization with high accuracy.

Contribution

The study provides the first experimental measurement of the Zurek-Kibble scaling exponent for fluxon formation in Josephson Junctions, validating theoretical predictions.

Findings

Measured scaling exponent σ = 0.27 ± 0.05

Confirmed agreement with the predicted σ = 0.25

Validated the Zurek-Kibble model for fluxon production

Abstract

It has been argued by Zurek and Kibble that the likelihood of producing defects in a continuous phase transition depends in a characteristic way on the quench rate. In this paper we discuss our experiment for measuring the Zurek-Kibble scaling exponent $\sigma $ for the production of fluxons in annular symmetric Josephson Tunnel Junctions. The predicted exponent is $% \sigma =0.25$, and we find $\sigma =0.27\pm 0.05$. Further, there is agreement with the ZK prediction for the overall normalisation.