Dark Lump Excitations in Bose-Einstein Condensates

We investigated the dynamics of two-dimensional matter-wave pulses in a Bose-Einstein condensate with disk-shaped traps. For the case of repulsive atom-atom interactions, a Kadomtsev-Petviashvili equation with positive dispersion is derived using the method of multiple scales. The results show that it is possible to excite dark lump-like two-dimensional nonlinear excitations in the Bose-Einstein condensate.