Study On Quantum Teleportation Of Discret Variables

With the development of information technique and quantum mechanics, a new subject — quantum information theory, which based on the law of quantum mechanics, comes into being. Quantum communication is an important branch of quantum information, embracing quantum teleportation, quantum dense coding, quantum key distribution and so on. Quantum teleportation is one of the most striking fields in quantum communication, and also a novel and interesting application of quantum mechanics as well as the essential element of quantum communication and quantum computation. So study on quantum teleportation is very meaningful not only to the development of quantum communication, but also to apprehending the inside of mechanics more deeply.In this dissertation, we have studied the therotical schemes for quantum teleportation of discret variables in the various cases, and proposed some methods of realizing teleportation in cavity QED and ion traps.1. Teleportation of muti-particle arbitrary quantum states. Teleportation of n-particle arbitrary quantum state by using n pairs of Bell states as quantum channel, when n is much large, ascertaining the corresponding relationship between the results of Alice's measurement and Bob's unitary transfomations one by one is not a simple thing. In this thesis, we proposed a simple way for ascertaining the corresponding relationship. Furthermore, we proposed a scheme for implementing probabilistic teleportation of n-particle arbitrary quantum state via n pairs of partially entangled pure state.2. Scheme for teleportation of an unknown multi-particle quantum state by using a single entangled pair as quantum channel. The feature of the scheme is that teleporting a mutlipartite state with a reduced amount of entanglement and costs less classical bits.3. Implementing teleportation in cavity QED. In this paper, we proposed a scheme for disdinguishing all the orthogonal and complete multi-atom GHZ states only by one step, Based on which a scheme for concentrating multi-atom partially entangled states and two methods of teleporting a multi-atom entangled state are also proposed.4. Implementing probabilistic teleportation between two separated trapped ions. In the scheme, Bob can recontruct internal state of ion 1 on ion 3 (the receiver of electronic state) with maximally probabiUty by controlling the interaction time between ion 3 and the laser standing wave in the ion trap B, after receiving the result of Alice's measurement on the subsystem of ion 1 and ion 2 in trap A.