Bose--Einstein solitons in highly asymmetric traps
  We obtain analytic solutions to the Gross-Pitaevskii equation with negative scattering length in highly asymmetric traps. We find that in these traps the Bose--Einstein condensates behave like quasiparticles and do not expand when the trapping in one direction is eliminated. The results can be applicable to the control of the motion of Bose--Einstein condensates. 
Victor M. Perez-Garcia, H. Michinel, H. Herrero