The Transmission Of Quantum States And Preparation Of Entangled States

We are riving in a highly developping world of information, the informa-tion science plays an important role in human lives and social development.But the existing information system such as electronic computer, communi-cation network, information detection and so on, their informative functionhas been approximately exhausted. At this critical time, the science of Quan-tum information was born. The science of Quantum information is the resultsof Quantum Mechanics'combination with the science of information, who canbreakthrough the physical limitation of existing informative technology andis endowed with huge potential power of bringing a reform to informationengineering. At present, Quantum information, as one of the most attrac-tive scientific research field, has became the focus of international scientificresearch, and is developping very fast.In this paper, we mainly discussed the quantum communication and thepreparation of entangled states in the quantum information field, and we haveproposed a scheme of perfect transmission of an arbitrary multi-particle state,which is implemented by using cluster state and the QED system. On thepreparation of entangled states, we have studied the preparation of clusterstate in the QED system, and also present an experimentally feasible proposal.Further more, these schemes have been analysed from the experimental point,and were proven their feasibility.In the part of prolegomenon, the science of Quantum information andour work were briefly described. The second chapter is about basic theoryof Quantum entanglement and a few of the most common entangled stateswere introduced. In the chapter three, we introduced the conception of tele-portation and the teleportation of N-particle state, and the cluster state andits properties, then, we discussed the scheme of multi-particle transmissionby cluster states in detail. And in the chapter four, the implementation ofquantum communication and entanglement preparation in the QED systemwas researched, at first, we have introduced the basic theory of QED system and QED system with an extra classic field respectively, and then detailedlypresented the scheme of teleportion of a multi-atom arbitrary state with ther-mal cavity and estimated the effects the experimental error had on the fidelity,after that, we have investigated the preparation of one-dimension cluster statein the QED system. And the last chapter is a conclusion and prospects of ourwork in this paper.