Cold Atom Dynamics In Quantum Microcavity

Recently, with the development of experiment technique in atomic optics , the behaviour of atom has been controlled, by the electromagnetic field in a quantum microwave cavity which is considerable small. The experimental and theoretical research of laser cooling and trapping of atoms has become a vigorous branch of physics. The realization of Bose-Einstein condensation (BEC) is one of the most important achievement of laser cooling.We study Dynamics of cold atoms in a quantum cavity based on quantum description of interactions between atoms and photon in this paper.Models have been established for the interaction between quantized laser field and cold atom The conditions of trapping of the cold atom are discussed in quantum cavity. The adiabatic dynamics of the interaction between quantized laser field and cold atom and non- adiabatic modification is discussedThe condition of adiabatic approximation for trapping of atoms is described quantitatively.The exchange of momentum between the mass center of a 2-level atom and a double modes field is studied.The More photons could be absorbed or emitted when number of photons can be controlled. Thus large translation of atoms mass center motion is realized.A model has been established for the interaction between a single-mode optical field and an energy-level 2 cold atom with exact analytic solutions given, the processes of momentum and energy exchanges between the optical field and the cold atom due to the interaction between them are discussed in detail, and a formula hasbeen given for the variation of momentum and energy exchange volumes with time t in dress state while both the effects of photon recoil and Doppler effect are taken into consideration.An approximation method to deal with the evolution of the quantized system with rapid and slow free degrees is given, combined the high-order adiabatic approximation (HOAA) and Born-Oppenheimer (BO) approximation .The motion of mass center is studied using Heisenberg representation, the correct orbit of mass center is gotten in the semiclassical limit. The internal levels are represented by Schrodinger representation, it becomes converieat to apply HOAA The high-order effect of motion of mass ceater of atom on dynamics of electron-field system is analyzed.With the high-order adiabatic effect of atoms mass center on the evolution of the atomic system of electron and light field as an illustration ,the influence of atoms motion on the quasi- adiabatic process of the atomic dressed state is analyzed in detail. The first-order approximation of non-adiabatic factor for the atomic transition is systematically discussed.The dynamics in the Bose-Einstein Condensation (BEC) process with interaction between two energy-level Bose atoms and single-mode active cavity field in the quantum cavity is analyzed using the ordinary method suggested by the authors for solving the wave function in the Schro'dinger idea from the Heisenberg idea. A wave function has been established for the atoms under the BEC conditions in the quantum cavity, and the factors having effect on the BEC stability in the quantum cavity and the rules for selecting quantum leaps are analyzed.