We apply the theory of the inhomogeneous Kibble-Zurek mechanism to understand the quench dynamics in the transition from a Mott insulator to a superfluid in a cold Bose gas confined in both a two-dimensional optical lattice and a harmonic trap. The local quench time and the resulting Kibble-Zurek diabatic-adiabatic boundary take a nontrivial positional dependence due to the Mott-lobe structure of the ground-state phase diagram of the Bose-Hubbard model. We demonstrate the quench dynamics through the time-dependent Gutzwiller simulations, revealing inhomogeneous properties of the growth of the superfluid order parameter. The inhomogeneous Kibble-Zurek theory is applicable to the shallow harmonic trap.

• Received 9 October 2020
• Accepted 24 December 2020

DOI:https://doi.org/10.1103/PhysRevA.103.013310