Collapse And Revival Effect In Two-Component Bose-Einstein Condensates

In this thesis , we study the following problems about two-component Bose-Einstein condensates (BEC) in theory:In chapter 2 , with the numerical calculation method we have investigated the dynamics of two-component BEC with coupling drive by the explicit expression of the second atomicity density , and we have also discussed the influence of the strength of the coupling drive .The strength of interspecies interaction , the rf frequencies and the strength of the interaction in each condensate on the time evolution properties of atomicity density is studied . Our results demonstrate that atomicity density fluctuates like a sinusoidal function of time approximately . And it is clear that with the increase of the strength of coupling drive or the strength of interspecies interaction , the period of oscillation of the atomicity density decreases . However , its period increases with the increase of the strength of the interaction in each condensate . Furthermore , the change of the rf frequencies does not affect fluctuation's period notably , both the increase of the rf frequencies and the strength of the interaction in each condensate will result in the decrease of the amplitude of oscillation.In chapter 3 , we have investigated the time evolution of atomicity density of two-component BEC with numerical calculation , and have found that the evolution of condensate density in long time , which presents a typical quantum collapse and revival with a complex period , is rather different from that in short time ,which displays a regular sinusoidal oscillation. Furthermore ,we have also discussed the influence of the Rabi frequency of coupling drive field .various values for the relative phase ,the strength of the coupling drive , the strength of the interatomic interaction in each condensate and the strength of the interspecies interaction on the evolution properties of atomicity density .In chapter 4 the influence of rf (radio frequency) frequencies on long time evolution of atomicity density of two-component Bose-Einstein condensations is studied . The research results demonstrate that the atomicity density of BEC...