Interference of the evolutions of Rb and Na Bose-Einstein condensates

Spin evolution of a mixture of two species of spin-1 Bose-Einstein condensates (Rb and Na) has been investigated beyond the mean field theory. Both analytical expression and numerical results on the populations of spin-components are obtained. The interference is found to depend on the initial states and the inter-species interaction sensitively. A number of phenomena arising from the interference have been predicted. In particular, periodic behavior and the alternate appearances of a zone of oscillation and a long quiet zone are found.