Finite number of vortices and bending of finite vortex lines in a confined rotating Bose-Einstein condensate
Department of Physics, Fudan University, Shanghai, 200433, P.R. China
Corresponding author: a email@example.com
Revised: 14 April 2006
Published online: 1 September 2006
The minimal energy configurations of finite Nv-body vortices in a rotating trapped Bose-Einstein condensate is studied analytically by extending the previous work [Y. Castin, R. Dum, Eur. Phys. J. D 7, 399 (1999)], and taking into account the finite size effects on z-direction and the bending of finite vortex lines. The calculation of the energy of the vortices as a function of the rotation frequency of the trap gives number, curvature, configuration of vortices and width of vortex cores self-consistently. The numerical results show that (1) the simplest regular polynomial of the several vortex configurations is energetically favored; while the hexagonal vortex lattice is more stable than square lattice; (2) bending is more stable then straight vortex line along the z-axis for λ<1; (3) the boundary effect is obvious: compared with the estimation made under infinite boundary, the finite size effect leads to a lower vortex density, while the adding vortex bending results in a less higher density because of the expansion. The results are in well agreement with the other authors' ones.
PACS: 03.75.Lm – Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices and topological excitations / 32.80.Pj – Optical cooling of atoms; trapping
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2006