远程信息集中：优化非对称经济1→3相位协变克隆之逆

摘要

研究基于优化非对称经济1→3相位协变克隆的远程信息集中问题。首先，以最大纠缠 W型态为量子信道，分别通过投影测量和半正定算子值测量，给出了两个远程信息集中协议，以非最大纠缠 W型态为量子信道，将上述协议进行了推广。其次，通过投影测量，并分别以最大纠缠 GHZ型态和四粒子团簇态为量子信道，提出了两个远程信息集中方案。当以最大纠缠 GHZ型态为量子信道时，远程信息集中成功的概率总为1；而以 W型态或团簇态为量子信道、信息集中成功的概率呈现出克隆态或量子信道之参数的函数形式。在以 GHZ型态、团簇态和 W型态这三种态为量子信道的信息集中协议中，前者之恢复操作最简单，第三个的恢复操作最复杂。最后，指出了上述协议都是安全和实验实现的。%The aim of this paper is to investigate remote information concentration (RIC)based on the optimal asymmetric economical 1→3 phase-covariant telecloning.Firstly,using maximally entangled W-type states as quantum channel, we put forth two RIC schemes by proj ective and POVM measurement,respectively.Moreover,we generalize the above protocols via non-maximally entangled W-type state as quantum channel.Secondly,by proj ective measurement,we propose two RIC protocols by employing maximally entangled GHZ-type and four-qubit cluster state as quantum channel,respectively. Comparing the above protocols,the probability of RIC is always one when maximally entangled GHZ-type state is employed as quantum channel,but for W-type and cluster state,the probabilities present functions about the parameters of cloning state or quantum channel.Among the GHZ-type state,cluster state and W-type state as quantum channel,the recovering operation for the former is simplest,but that for the last is most complex.Finally,we obtained that the above protocols are securie and experimental realization.