arXiv:0906.4259 · Physical Review A
Vortices in Bose-Einstein condensates with dominant dipolar interactions
Marta Abad, M. Guilleumas, R. Mayol, Martí Pi, Dora M. Jezek
Abstract
We present full three-dimensional numerical calculations of single vortex states in rotating dipolar condensates. We consider a Bose-Einstein condensate of $^{52}\text{C}\text{r}$ atoms with dipole-dipole and $s$-wave contact interactions confined in an axially symmetric harmonic trap. We obtain the vortex states by numerically solving the Gross-Pitaevskii equation in the rotating frame with no further approximations. We investigate the properties of a single vortex and calculate the critical angular velocity for different values of the $s$-wave scattering length. We show that, whereas the standard variational approach breaks down in the limit of pure dipolar interactions, exact solutions of the Gross-Pitaevskii equation can be obtained for values of the $s$-wave scattering length down to zero. The energy barrier for the nucleation of a vortex is calculated as a function of the vortex displacement from the rotation axis for different values of the angular velocity of the rotating trap.