Quench dynamics of tunable Bose gases in an optically painted 2D box

A quantum gas loaded in an optical box presents a model homogeneous system for exploring quantum many-body dynamics. While trap uniformity has been the main attraction for realizing intricate many-body states or for studying non-equilibrium dynamics without suffering from inhomogeneous effects, the existence of sharp edges in a box could also lead to unexpected, but fascinating consequences in out-of-equilibrium dynamics that were not seen in conventional harmonic traps. In this talk, I will discuss two examples of quench dynamics from atomic superfluids trapped in two-dimensional (2D) boxes. I will first present our recent studies of interaction quenches to attractive Bose gases, where we observe instability-induced quasiparticle pair-creations and can characterize their quantum entanglement. This dynamics in a uniform trap eventually leads to fragmentation and formation of solitons among other intricate dynamics. In the second example, I will discuss quench dynamics of a repulsive Bose gas and show how the interaction with the box boundary could lead to spontaneously patterned defect formation in a superfluid - from ring dark solitons to vortex dipole necklaces - which would open a doorway towards forming complex vortex quantum matters in an optical box. I will discuss our on-going studies on out-of-equilibrium dynamics using tunable Bose gases in optically painted 2D boxes.