Decay of soliton-like perturbations into vortex - anti vortex pairs
  This paper suggests a method for an experiment to create dark soliton-like waves in a trapped atomic Bose-Einstein condensate (BEC). With the phase imprinting method, a soliton-like disturbance is produced along the x-axis. The method is used in two cases (with and without rotation of an asymmetric trapping potential). The disturbance in a two-dimensional system is unstable. The soliton-like perturbation is found to decay into more stable vortex pairs together with a burst of sound wave. The simulations are performed by solving the two-dimensional Gross-Pitaevskii equation (2D GPE). The successive dynamics of the wave function are studied by monitoring the evolution of density and phase profile. 
Eniko J. M. Madarassy