Generation of higher-order atomic dipole squeezing in a high-Q micromaser cavity. (VI). Atomic damping by a squeezed vacuum

In our previous serial works, we investigated the generation of higher-order atomic dipole squeezing (HOADS) in a high-Q micromaser cavity. In this paper, we continue to study HOADS in this system but consider the effect of atomic damping by a squeezed vacuum in the absence of an external field. The corresponding master equation is introduced and its solutions for an initial SU(2) coherent state of the atom are presented. In the absence of the atomic damping, we have shown that stable and permanent HOADS can be generated by properly preparing the atom in certain SU(2) coherent state. We demonstrate the destructive effect of atomic damping on HOADS by changing the initial atomic coherence or the average number of the reservoir photons. The relation between HOADS and second-order atomic dipole squeezing (SOADS) is discussed. It is found that the atomic damping has more destructive effects on SOADS than on HOADS.