Symmetry Breaking and Critical Scaling in Ultracold Quantum Gases

Driving a physical system abruptly through a continuous phase transition leads to a variety of interesting physical phenomena, including spontaneous formation of topological defects such as solitons, vortex lines, and monopoles. This is a universal phenomenon which is relevant to systems as diverse as ultra-cold quantum fluids and the cooling of the universe shortly after a `hot big bang'. The critical behavior of these systems is not determined by local dynamics, but rather by universal scaling laws arising from key global parameters (e.g. dimensionality, spin degrees of freedom, interaction range) . Laboratory tests of of these critical scaling theories have to date proven to be challenging, with some limited success. We are using new techniques for controlling ultracold (Fermi and Bose) gases to try to more rigorously test some of these critical scaling predictions.