Quantum Entanglement Of Two-body In The CQED

The mechanism of quantum entanglement and quantum entanglement measure is an important issue in quantum information science, is the cornerstone of quantum communication and quantum computers. Theoretical and experimental progress in recent years tells us that entanglement for quantum information processing, is essential, easy integration, storage, and entangled qubits, quantum information will only be meaningful only in the possible physical system. At the same time, the quantum entanglement measure is a numerical representation of the quantum entanglement can be more convenient, intuitive features of entanglement between bits. The paper first introduces the basic concepts of quantum entanglement and the density matrix characteristics and meet the requirements, then focus on the two-body system qubits entanglement measure is an overview of pure state entanglement for two-body part of the entropy, the two-body entangled mixed state commonly used to the Concurrence measure, Concurrence is method in the two qubits system is the most mature, most "good" measure, but is no longer applicable for high-dimensional system of two-body can only use the Negativity metric method, as to three body and three more than the many-body entangled, today is not a recognized measure. CQED, it is mainly of atoms and cavity mode electromagnetic field interactions, provides an exploration of entanglement properties and system dynamics characteristics of different environments. We introduce three kinds have been widely used maturity model:(1) free space in the two atoms and the surrounding environment (thermal reservoir) interaction,(2) two atoms and a cavity field interaction,(3) separation of the field interaction of two atoms and where the single-mode cavity field. We see, a different initial state, the cavity Q is worth the high and low, a direct result of the entanglement evolution of the same features. In addition, in the singular feature of entanglement, such as entanglement sudden death of entanglement resurrection, entanglement phenomenon of conversion of simple research and discussion. The basis of quantum entanglement, a general overview of a variety of known maturity model, corresponding to contain all the information of the system density matrix, trying to find the entangled and entanglement characteristics produce physical mechanism.