Quench dynamics of an ultracold two-dimensional Bose gas

We study the dynamics of a two-dimensional Bose gas after an instantaneous quench of an initially ultracold thermal atomic gas across the Berezinskii-Kosterlitz-Thouless phase transition, confirming via stochastic simulations that the system undergoes phase ordering kinetics and fulfills dynamical scaling hypothesis at late-time dynamics. Specifically, we find in that regime the vortex number decaying in time as $\langle N_v \propto t^{-1}\rangle$, consistent with a dynamical critical exponent $z \approx 2$ for both temperature and interaction quenches. Focusing on finite-size box-like geometries, we demonstrate that such an observation is within current experimental reach.