Entanglement in the system of two coupling atoms with a single-mode squeezed vacuum field are studied by means of quantum theory.Using the numerical method,the relation between the entanglement and the coupling parameter and initial state of the system is discussed.
The entanglement in the system which consists of two-mode squeezed vacuum state and Bose- Einstein condensate in two-photon process is investigated.The entanglement of field-atom and the entangle- ment between the two-mode field are investigated using the quantum reduced entropy and quantum relative entropy,respectively.The influences of the initial squeezed parameter of field and the interaction between atoms on the evolution of the entanglement of field-atom and one of two modes of field are discussed.