Entanglement in a Two-Boson Coupled System

A model for two nondegenerate cavity fields coupled through a reservoir is considered. Such a model can be employed for the study of Raman scattering in which the Stokes and anti-Stokes fields indirectly interact via a bath of phonon. An analysis for appearance of quantum entanglement between the fields and evaluation of the entanglement measure depending on initial states of the fields and on a state of the phonon reservoir is given.