Quantum Entanglement and Nonclassical Properties of Three Two-Level Atoms Interacting with a Single-Mode Field in the Presence of Intensity-Dependent Coupling

This paper describes the interaction of three two-level atoms with a single-mode quantized field in the intensity-dependent coupling regime. Under a choice for the initial conditions for subsystems, where the atoms are prepared in the excited state and the cavity field is in the standard coherent state, the explicit form of the state vector of the whole system are obtained. To achieve this goal, the Laplace transform technique can be applied. By considering the intensity-dependent and constant coupling regimes, some of the most important physical properties of the system such as quantum entanglement between the atomic subsystem and the radiation field subsystem, atomic population inversion, quantum statistics of photons, and quadrature squeezing are numerically investigated. The numerical results show that the presence of nonlinear function can affect in the depth and the domain of the nonclassicality of the system. Also, by choosing different nonlinearity functions corresponding to any nonlinear oscillator with arbitrary nonlinear function, or corresponding to any solvable quantum system with a known discrete spectrum, the presented formalism would clearly be distinguished.