Study Of Entanglement In A Nonlinear System

As one of the most marked distinctions of quantum mechanics and classical mechanics, entanglement has attracted a lot of attention on fundamental research since the quantum information came into being in the past century. There were a series of breakthroughs in quantum information and computation, which make these two subjects become front-line of science all over the world. As the information carrier, the preparation and effective measurement have been being the key problems in the study of theoretical principle and experiments.The so-called optical lattice system is such as the atoms in the standing wave field which are bound in space by the spontaneous emission and dipole force. We can control the atoms by control the field due to the interaction between atoms and laser field. The system can realize some quantum information process efficiently. The quantum entanglement and related problems are studied, as well as those related to thermal entanglement. In this paper we introduce an optical lattices system with nonlinear couplings, which describe entanglement of two atoms only. By studying the entanglement and entanglement capability and its application in quantum information and computation of the system, we can study and understand this system concretely. Its entanglement and entanglement capability are discussed. The two-partite entanglement is discussed for the involved system, as well as the entanglement capacity deduced from the dynamical evolution. And the thermal entanglement and entanglement capacity are analyzed also in this paper. The form of well-known EPR state and the reversal logic gate can be realized.