Non-equilibrium dynamics in Mott-to-superfluid transition in Bose-Einstein condensation in optical lattices

Bose-Einstein condensates of cold atoms in optical lattices are interesting because the dynamics of the transition from a Mott insulator to a superfluid driven by a quench into the superfluid phase exemplifies non-equilibrium evolutions of gauge-symmetry broken quantum phases-Here we have actually visualised features in real space-which have domain structures that depend on the stage of the transition dynamics-Namely-the system after the quench relaxes in three processes: (i) an exponential growth of the superfluid density, (ii) collapse of the domain structure, and (iii) vortex-antivortex pair-annihilation as the long-range superfluid order is formed-Topological picture due to Kibble-Zurek mechanism and Zurek's freeze-out scenario for slow quenches are confirmed