We present a （t, .n） threshold multiparty controlled quantum teleportation protocol of an arbitrary m-qubit quantum state between two remote parties. The unknown m-qubit quantum state can be recovered by the receive...We present a （t, .n） threshold multiparty controlled quantum teleportation protocol of an arbitrary m-qubit quantum state between two remote parties. The unknown m-qubit quantum state can be recovered by the receiver under control of a subset of the n controllers if the number of the subset is larger than or equal to a threshold, say, t, but not for any t - 1 or fewer controllers. Our scheme seems to be more practical and more flexible than other existing protocols. The quantum resource required is just m Einstein-Podolsky-Rosen （EPR） pairs plus some single photons. The techniques required are only Bell state measurement, single-qubit unitary operation and yon Neumann measurement. So our scheme is also feasible with present-day technique.展开更多
基金Supported by the National Basic Research Program of China (973 Program) under Grant No.2007CB311100the National Natural Science Foundation of China under Grant No.60873191+3 种基金the National High Technology Research and Development Program of China under Grant No.2006AA01Z419the Major Research plan of the National Natural Science Foundation of China under Grant No.90604023the Scientific Research Common Program of Beijing Municipal Commission of Education under Grant No.KM200810005004the Scientific Research Foundation for the Youth of Beijing University of Technology under Grant No.97007016200701
文摘We present a （t, .n） threshold multiparty controlled quantum teleportation protocol of an arbitrary m-qubit quantum state between two remote parties. The unknown m-qubit quantum state can be recovered by the receiver under control of a subset of the n controllers if the number of the subset is larger than or equal to a threshold, say, t, but not for any t - 1 or fewer controllers. Our scheme seems to be more practical and more flexible than other existing protocols. The quantum resource required is just m Einstein-Podolsky-Rosen （EPR） pairs plus some single photons. The techniques required are only Bell state measurement, single-qubit unitary operation and yon Neumann measurement. So our scheme is also feasible with present-day technique.
