Dynamics of a two-component atomic Bose-Einstein condensate
  The dynamical population oscillations between two internal states of a Bose-Einstein condensate are investigated within the rotating wave approximation. Analytical expressions for the population imbalance in the number states and coherent states have been derived, which predict different revival periods. Thus the true quantum state of the condensates may be unambiguously determined by detecting the atom intensity evolution for one internal state. 
Ping Zhang, C.K. Chan, Xiang-Gui Li, and Xian-Geng Zhao