The Molecule Production Rate In A Λ Configuration Atom-molecular Three-level System

In this thesis, we investigated the quantum dynamics of the Aconfiguration atom-molecular three-level system analytically and numerically.Based on these, the production rate of molecule is studied under the variousinitial conditions. Starting from our theoretical results, we discussed theproduction rate of the ultra-cold molecule by the photo-associated method.Our results show that the production rate dependents on the initial condition.In the case of ideal case, one can have completely transformation with theresonant Rabi frequency for the atom initial state. While for the dark state,the production rate is constant. But the production rate usually is bigger thanthe initial value when the dark state is destroyed. The detune of the couplingoptical field usually decrease the production rate for atom state, but increasefor dark state, and the influence of atom state is smaller than the dark state's.Moreover one can have the biggest production rate in resonance condition forthe atom initial state. But for the dark state, the condition is antithesis. Wecan control the transformation of particle make use of the tunabletime-dependent Rabi frequency. The influences of decay are same for eachinitial state and the production rate is inverse proportion to the decay.