Hydrodynamic approach to vortex lifetimes in trapped Bose condensates - art. no. 063612

We study a vortex in a two-dimensional, harmonically trapped Bose-Einstein condensate at zero temperature. Through a variational calculation using a t rial condensate wave function and a nonlinear Schrodinger Lagrangian, we ob tain the effective potential experienced by a vortex at an arbitrary positi on in the condensate, and find that an off-center vortex will move in a cir cular trajectory around the trap center. We find the frequency of this prec ession to be smaller than the elementary excitation frequencies in the clou d. We also study the radiation of sound from a moving vortex in an infinite , uniform system, and discuss the validity of this as an approximation for the trapped case. Furthermore, we estimate the lifetime of a vortex due to imperfections in the trapping potential.