Dynamical nonlinear excitations induced by interaction quench in a two-dimensional box-trapped Bose-Einstein condensate

Manipulating nonlinear excitations, including solitons and vortices, is anessential topic in quantum many-body physics. A recent progress in thisdirection is a new protocol proposed in [Phys. Rev. Res. 2, 043256 (2020)] toproduce dark solitons in a one-dimensional atomic Bose-Einstein condensate(BEC) by quenching inter-atomic interaction. Motivated by this work, wegeneralize the protocol to a two-dimensional BEC and investigate the generalscenario of its post-quench dynamics. For an isotropic disk trap with ahard-wall boundary, we find that successive inward-moving ring dark solitons(RDSs) can be induced from the edge, and the number of RDSs can be controlledby tuning the ratio of the after- and before-quench interaction strength acrossdifferent critical values. The role the quench played on the profiles of thedensity, phase, and sound velocity is also investigated. Due to the snakeinstability, the RDSs then become vortex-antivortex pairs with peculiardynamics managed by the initial density and the after-quench interaction. Bytuning the geometry of the box traps, demonstrated as polygonal ones, moresubtle dynamics of solitons and vortices are enabled. Our proposed protocol andthe discovered rich dynamical effects on nonlinear excitations can be realizedin future cold-atom experiments.