  We investigate the nonequilibrium dynamics of two-dimensional Bose-Einstein
condensates in boxlike traps with power-law potential boundaries by quenching
the interatomic interactions. For both concave and convex potentials, we show
that ring dark solitons can be excited during the quench dynamics. The
modulation strength of the quench and the steepness of the boundary are two
main factors affecting the evolution of the system. Five dynamic regimes are
identified concerning the number of ring dark solitons excited in the
condensate. For the situation without ring dark soliton excitations, the
condensate undergoes damped radius oscillation. As far as the appearance of
ring dark solitons, interesting structures arise from their decay. For the
concave potential, the excitation patterns show a nested structure of
vortex-antivortex pairs. For the convex potential, on the other hand, the
dynamic excitation patterns display richer structures that have multiple
transport behaviors.
