Evidence for Long-Range Correlations within Arrays of Spontaneously Created Magnetic Vortices in a Nb Thin-Film Superconductor

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 ${10}^9\mathrm{K}/\mathrm{s}$. The spontaneous appearance of vortices is predicted by the Kibble-Zurek and by the Hindmarsh-Rajantie models of phase transitions under nonequilibrium conditions. Differentiating between these models requires a measurement of the internal correlations within the emerging vortex array. In addition to short-range correlations predicted by Kibble and Zurek, we found unexpected long-range correlations which are not described by any of the existing models. DOI: http://dx.doi.org/10.1103/PhysRevLett.104.247002 © 2010 The American Physical Society