Quantum State Preparation And Application In Cavity QED

Quantum information is a new subject in order to research the quantum information processing, which uses the basic principles of quantum mechanics in information science related field. Quantum entanglement is a very important research object in the quantum information. It is the foundation of realizing safety quantum communication. Cavity quantum electrodynamics (cavity QED) is one of physical system which can realize the quantum entanglement. Cavity QED research photon and atom in the narrow lumen, specific boundary conditions of the interaction.Quantum entanglement is the basic physical resources in the quantum communication. In all aspects of quantum information, such as quantum recessive transmission, quantum key distribution and quantum computation and so on, it plays an important role in the related field. Entanglement system is experimental conditions, the influence of environmental noise, the entanglement produce away coherent function, use the entangled state in the quantum communication will lead to information distortion. Therefore, in quantum communication, need to accurately identify and entanglement of entanglement purification can guarantee the reliable transmission quantum state, how to realize the entangled state to identify and improve the entanglement purification is also an important subject of quantum communication. The main content of this paper is based on cavity QED entangled state of preparation and application of the theory research. The paper main work involved in the following aspects:1. Use a new type of cavity preparation entangled state. The first analysis of the cavity of the reflection and transmission characteristics, and then in cavity QED system, we use the photon and cavity interaction rules, the use of nondestructive measurement principle, preparation of entangled state, including bell state and GHZ state, finally simulation chamber of the reflection and transmission to the influence of the success rate of entanglement. In the strong coupling conditions, entangled state success probability close to1.2. In the fifth chapter of the paper, simply introduces the application of entanglement. In this chapter, a kind of entanglement purification methods, using the incident photon after entering system, achieve the effect of parity, finally using cavity QED system achieve entanglement purification.