Atom and field squeezed output of three-level atom laser surrounded by a Kerr medium in the electromagnetically induced transparency regime

In this paper, we investigate the squeezing properties of the output of an atom laser which consists of an ensemble of three-level atoms in Bose-Einstein condensate state interacting with two quantized and classical laser fields in the presence of a Kerr medium. We represent the Hamiltonian of the system under an electromagnetically induced transparency regime and using the adiabatical elimination process, in terms of angular momentum operators, and then deduce the corresponding analytical state vector with the help of the Dicke model. We give our attention to the evaluation of atomic and field squeezings via numerical calculations. The results show that nonlinear sources in the system, i.e., "interatom collisions" and "Kerr medium," lead to squeezing of atoms and photons. In this respect, the squeezing values can be controlled by adjusting the strength of interatom collisions, the Kerr medium, as well as other involved parameters in the considered model. Also, the collapse-revival phenomenon as a pure quantum feature can be observed in the behavior of atomic squeezing, while only irregular oscillations appeared in the field squeezing. (C) 2017 Optical Society of America