Schmidt Decomposition Of The Three-particle States Probabilistic Teleportation And The General State Of Two Particles Of The Probability Of Transmission Measurement With Povm

Quantum information is a new subject that is a combination of physics science and information science. Quantum information which is based on the basic theory of quantum mechanics researches mainly quantum computer, quantum communication, quantum key distribution and so on. If the characteristic of quantum system is applied to the information field, people can exceed the limit about classical information in many aspects and realize the function that is the decomposability of great gene, quantum teleportation and absolute safe code, which the classical information can't achieve. The naissance of quantum information offers the reliable physical base for the transformation of tomorrow's science and new theory for the twenty-first century's development about information science.Quantum teleportation is a novel and funny problem, which is a wonderful application of the characteristic of quantum mechanics, its basic element is as following: for realizing teleporting an unknown quantum state, the information about protoplast is divided into two parts that is classical information and quantum information. The receiver gains classical information through the sender's measuring protoplast and gains quantum information that is the rest information that the sender doesn't pick up. After the receiver gains the two kinds of information, he can make the ideal duplication about protoplast. That is to say, using quantum entanglement, the sender does not sent any qubit but send an unknown quantum state, that is quantum teleportation.The decoherence may arise because of the interaction between quantum channel and environment. At present, quantum channel is always not maximally entangled state. So in chapter III and chapter IV, we present two schemes for probabilistic teleportation. One is the probabilistic teleportation about the Schmidt decomposition of three-quantum-bit state, the other is the probabilistic teleportation about the general formation of two-quantum-bit state. The former scheme uses non-maximally entangled states as quantum channel, By introducing an auxiliary particle and performing a collective unitary operation, the latter one also uses non-maximally entangled states as quantum channel, By introducing two auxiliary particles and performing POVM measurement, so two kinds of teleportation will succeed with certain probability.