Coherent disintegration and stability of vortices in trapped Bose   condensate
  We consider the intrinsic stability of the vortex states of a pure Bose-Einstein condensate confined in a harmonic potential under the effects of coherent atom-atom interaction. We find that stable vortices can be supported, and that vortex stability can be controlled by changing the inter-particle interaction strength. At unstable regimes, a vortex will spontaneously disintegrate into states with different angular momenta even without external perturbations, with the lifetime determined by its imaginary excitation frequencies. 
H. Pu, C.K. Law, J.H. Eberly, and N.P. Bigelow