REDUCING FOUR-LEVEL TWO-MODE HAMILTONIAN TO AN EFFECTIVE TWO-LEVEL HAMILTONIAN WITH THE ADDITION OF KERR-LIKE MEDIUM

摘要

We consider a two-mode quantized field described in a coherent state interacting with a four-level atom. An effective Hamiltonian is obtained by adiabatically eliminating the intermediate two levels in a cascade process. The influence of the Stark shifts and the Kerr-like medium on the atomic inversion are examined, as well as on the field entropy,atomic purity and Mandel’s Q-parameter. The results of the calculations are illustrated numerically.