Excited Coherent Modes of Ultracold Trapped Atoms
  A method of exciting coherent spatial modes of Bose-condensed trapped atoms is considered. The method is based on the resonance modulation of the trapping potential. The population dynamics of coherent modes is analysed. The method makes it possible to create mixtures of different spatial modes in arbitrary proportions, including the formation of pure excited coherent modes. Novel critical effects in the population dynamics are found. 
V. I. Yukalov, E. P. Yukalova, and V. S. Bagnato