We have imaged spontaneously created arrays of vortices (magnetic flux quanta), generated in a superconducting film quenched through its transition temperature at rates around 109K/s. Spontaneous appearance of vortices is predicted by Kibble-Zurek and by Hindmarsh-Rajantie models of phase transitions under non-equilibrium 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.
@article{arxiv.0911.5613,
title = {Correlations beyond the horizon},
author = {Daniel Golubchik and Emil Polturak and Gad Koren},
journal= {arXiv preprint arXiv:0911.5613},
year = {2009}
}