Vortices in dipolar condensates with dominant dipolar interactions

TL;DR

This paper provides detailed three-dimensional numerical solutions for vortex states in rotating dipolar Bose-Einstein condensates, exploring the effects of dipolar and contact interactions and calculating critical velocities and energy barriers.

Contribution

It offers the first exact solutions of the Gross-Pitaevskii equation for pure dipolar interactions in vortex states, extending beyond variational approximations.

Findings

Exact vortex solutions obtained for zero s-wave scattering length.

Critical angular velocities calculated for various interaction strengths.

Energy barriers for vortex nucleation mapped as a function of vortex displacement.

Abstract

We present full three-dimensional numerical calculations of single vortex states in rotating dipolar condensates. We consider a Bose-Einstein condensate of 52Cr 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.