Probing non-equilibrium quench dynamics in a homogeneous two-dimensional Bose gas

Two-dimensional (2D) quantum gases in an arbitrarily painted box potential offers a versatile platform for studying non-equilibrium dynamics which may be difficult to realize in samples loaded into conventional harmonic traps. In this poster, we present our investigations of several quench-induced dynamics under different scenarios: 1) fragmentation and formation of matter-wave Townes solitons under attractive interactions, and 2) observation of spontaneous defect formation in a 2D superfluid. Our studies of 2D Townes solitons unveil a set of scale-invariant and universal scaling behaviors at negative atomic interactions. The observed defect formation in a superfluid results from atomic interaction with a quenched circular box under repulsive interaction strengths. We report observation of ring-shaped dark solitons emerging from the edge, and its evolution under a transverse (snaking) instability at discrete azimuthal angles. This results in a patterned formation of vortex dipole necklace. Furthermore, through in situ density noise measurements, we present direct characterization of coherence and even quantum entanglement within box-trapped quantum gases following interaction quenches.