Abstract
The interaction between an ultracold cascade three-level atom and a two-mode cavity field has been studied. The effects of the centre-of-mass motion, the cavity length, the coupling constants, the initial field states and the initial field intensity on the atomic dynamics have been examined. We have found that the population probabilities show dependence on the interaction time in the fast-atom region while they show dependence on the interaction length in the slow-atom region. The variations of the probabilities versus the cavity length show resonant peaks, and the peaks become sharper as the atom moves more slowly. The coupling constants, the initial field states and the initial field intensity also influence the atomic dynamics significantly. The two transitions are competitive for the atomic probability in the middle state, while they are cooperative for that in the lower state.