Simulating Cosmological Evolution by Quantum Quench of an Atomic BEC

Abstract: In cosmological evolution, it is the homogeneous scalar field (inflaton) that drives the universe to expand isotropically and to generate standard model particles. However, to simulate cosmology, atomic gas research has focused on the dynamics of Bose-Einstein condensates (BEC) with continuously applied forces. In this paper we argue a complementary approach needs also to be pursued; we, thus, consider the analogue BEC experiments in a non-driven, closed atomic system. We implement this using a BEC in an optical lattice which, after a quench, freely transitions from an unstable to a stable state. This dynamical evolution displays the counterpart "preheating", "reheating" and "thermalization" phases of cosmology. Importantly, our studies of these analogue processes yield tractable analytic models. Of great utility to the cold atom community, such understanding elucidates the dynamics of non-adiabatic condensate preparation.