Nonclassical effects in a three-level atom one-mode system with arbitrary forms of nonlinearities

A general formalism of a three-level atom single-mode system by including arbitrary forms of nonlinearities of both the field and the intensity-dependent atom–field coupling is proposed. With an arbitrary initial condition, an exact analytical time-dependent solution is presented. The work here extends previous studies in this context. Under the condition of an initial coherent field, the atomic-level occupation probability shows the collapse–revival phenomena, which have different features with different forms of the nonlinearities. We derive an expression for the Pancharatnam phase for the entangled state of the system. It is shown that the Pancharatnam phase explicitly contains information about the statistics of the field and atomic coherence. Also, the influences of the nonlinearities on the squeezing phenomenon and the correlation functions are examined.