Photon Entanglement Generation And Its Application In Quantum Communication

Since1935, people have paid widely attention to quantum entanglement. Quantum entanglement is the most exotic and the most incredible feature where quantum mechanics is different from classical physics. The entangled state plays a very important role in quantum information science. And it can be said that there would be no so-called quantum information without the phenomenon of quantum entanglement. Due to the special physical properties of entangled states, quantum information has got many new features that classical information has not. Meanwhile the entangled states also provide new physical resources for information processing and information transmission.With the development of quantum information science in recent years, people have done much work on quantum entanglement. Due to the non-local property, quantum entanglement was widely developed and used in quantum information-especially in quantum communication.This paper describes the basic principles of quantum entanglement, mainly discusses the preparation of photon entangled state via linear optical circuits and quantum non-demolition detector (QND):including the preparation of two-photon Bell-state, three-photon GHZ state and three-photon entangled W state. This dissertation discusses two applications of photon entanglement in quantum communication:quantum teleportation and quantum dense coding.