Impact of anisotropy on vortex clusters and their dynamics
Zentrum für Optische Quantentechnologien, Universität Hamburg - Luruper Chaussee 149, 22761 Hamburg, Germany, EU
2 Department of Mathematics and Statistics, University of Massachusetts - Amherst, MA 01003-4515, USA
Accepted: 10 January 2011
We investigate the effects of anisotropy on the stability and dynamics of vortex cluster states which arise in Bose-Einstein condensates. Sufficiently strong anisotropies are shown to stabilize states with arbitrary numbers of vortices that are highly unstable in the isotropic limit. Conversely, anisotropy can be used to destabilize states which are stable in the isotropic limit. Near the linear limit, we identify the bifurcations of vortex states including their emergence from linear eigenstates, while in the strongly nonlinear limit, a particle-like description of the dynamics of the vortices in the anisotropic trap is developed. Both are in very good agreement with numerical results. Collective modes of stabilized many vortex cluster states are demonstrated.
PACS: 03.75.Lm – Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations / 67.90.+z – Other topics in quantum fluids and solids (restricted to new topics in section 67) / 67.85.De – Dynamic properties of condensates; excitations, and superfluid flow
© EPLA, 2011