Spontaneous Fluxon Formation in Annular Josephson Tunnel Junctions

TL;DR

This paper reports an experiment measuring the Zurek-Kibble scaling exponent for fluxon production in Josephson Tunnel Junctions, confirming theoretical predictions with experimental data.

Contribution

First experimental measurement of the Zurek-Kibble scaling exponent in Josephson Junctions, validating theoretical models of defect formation during phase transitions.

Findings

Measured sigma = 0.27 +/- 0.05, close to predicted 0.25

Confirmed Zurek-Kibble scaling in Josephson Junctions

Agreement with theoretical normalization

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 +/- 0.05. Further, there is agreement with the ZK prediction for the overall normalisation.