Study On Controlled Quantum Cryptography Of Single_Particle Entanglement

Quantum information is a new crossing subject which emerged at the late of the twentieth century .It is the combination of quantum mechanics and information science, provide new principles and methods for information science and technology. When quantum information come out, it is interesting for physicist, communication scientist and mathematician. Nowadays, there are some investigations of quantum communication and quantum computation in quantum information science. The new domain as quantum countermeasure is also developing fast, and theoretical and experimental researches have great evolution. And quantum teleportation is one of the important content of quantum information science.There is a brief introduce of quantum teleportation's postulate, and then compute the Von Neumann entropy of the J-C model with high detuning, analyzed the physical purpose and the rule of the change. At last, we introduce four kinds of controlled methods using single-particle entanglement.