When applying two counter-propagating laser beams to a cold cloud of Rubidium atoms, we observe the spontaneous formation of intensity patterns associated with a spatial structuration of the atomic spins. We study the average number of defects in these patterns as a function of the sweep time employed to cross the transition threshold. We observe a power-law decrease of the number of defects with increasing sweep time, typical of the Kibble-Zurek mechanism. The measured exponent is consistent with the prediction for a supercritical bifurcation.
@article{arxiv.1610.00917,
title = {Kibble-Zurek mechanism in the self-organization of a cold atomic cloud},
author = {Guillaume Labeyrie and Robin Kaiser},
journal= {arXiv preprint arXiv:1610.00917},
year = {2017}
}