Abstract: From the viewpoint of the quantum information theory, the J-C Model of an atom interacting with a single-model light-field is expanded to a union physical system model which consists of M(where M is any positive integer) pairs of two-level atoms and the M cavity-field with interaction respectively. By solving the evolution matrix of the system state vector, the process of the atoms interacting with the light-field is studied and the principle of exchange and preservation of quantum entanglement information in this system is discussed. It is found that not only the atom entanglement but also the light-field entanglement can be transferred and preserved under different time conditions. At the same time, the different form entanglement states can be prepared by using the interaction of the atoms with the cavity-field.

Key words: quantum informatics, cavity quantum electrodynamics, entanglement exchange, entanglement preservation, entanglement preparation