Quantum entanglement and coherence in a system of four-level atom interacting with a nonlinear field

Abstract

Entanglement and atomic coherence are investigated for a system that consists of a four-level atom (FLA) coupled with a nonlinear field. We explore the influence of field deformation and photon transition on the dynamical behavior of the quantum measures when the quantized field is initially in a coherent state or in a Schrödinger cat state with and without energy dissipation. The results indicate that the entanglement and coherence in the FLA–field system can be controlled and manipulated through the nature and initial state of the quantized field.