Research On Controlled Teleportation Of Two-particle And Three-particle Entanglement

The quantum information science is an emerging subject,combined by the quantum mechanics and the information science. It includes the quantum communication and the quantum computation. In the quantum information science, the quantum entanglement is essential. Based on it, some area such as the quantum teleportation has been obtained important breakthrough. The quantum teleportation constituted the important content of the quantum communication and the quantum computation. Deep researches on the quantum teleportation will profoundly influence on the basic principle of the quantum information and on the future of quantum information communication, and will further reveal the physics connotation of the quantum mechanics.In this thesis, by using the quantum entanglement and the quantum information, some computations on the teleportation and the controlled teleportation were performed. A new kind of three-particle entanglement that different from the GHZ state and W state was chose as the quantum channel in the teleportation. Through our computation, it could also achieve the teleportation of two-particle general state with the three-particle entanglement as the quantum channel.Our attention was on the controlled teleportation. The controlled teleportation of two-particle general state with one largest EPR state and one largest W state as the quantum channels was obtained, and with two controllers. The receiver could receive the two-particle general state entirely when two controllers cooperated. Calculated the fidelity of the receiver received quantum state, when one or two controllers did not cooperate. The relation between the fidelity and the coefficient of the quantum state, regardless of the controllers whether or not to participate was obtained. The receiver could obtain the quantum state of the sender with 100% of the probability. This result was different from that of other authors.In the last part of this thesis, the controlled teleportation of three-particle general state with n controllers was discussed. If some controllers did not cooperate, calculated the relation between the fidelity and the coefficient of the quantum state, a result different from other entanglement as quantum channel was obtained.