Dynamics of a trapped atom interacting with an electromagnetic wave of circular polarization

In this paper the dynamics of a trapped two-level atom interacting with a b eam of electromagnetic wave of circular polarization is studied. In a frame rotating with the atomic transition frequency omega(o), the motion of the atom is governed by a nonlinear coupled Jaynes-Cummings (JC) Hamiltonian. B y means of this nonlinear Hamiltonian, we study the atomic inversion, squee zing effect of the vibration mode and that of the atomic dipole, and the ph ase property as well as its fluctuation of the vibration made. In the Lamb- Dicke limit, we get the results similar to those of the JC model; beyond th e Lamb-Dicke limit, we find the evolution of these quantities becomes very complicated. The nonlinearity weakens the collapse-revival phenomenon of th e atomic inversion and the squeezing effect; the evolution of the cosine ph ase operator becomes less predetermined with its fluctuation not enlarged.