Eur. Phys. J. D 41, 163-170 (2007)
https://doi.org/10.1140/epjd/e2006-00195-x

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 ylma@fudan.ac.cn

Received: 16 August 2005
Revised: 14 April 2006
Published online: 1 September 2006

Abstract

The minimal energy configurations of finite N_v-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.