未知EPR态及其正交态的概率复制

纠缠态在量子计算和量子信息中起着十分重要的作用。利用部分纠缠态作为资源提出了一种方案，根据该方案，能够以某些概率成功地复制出未知的EPR(Einstein Podolsky Rosen)态和它的正交态，使得通信双方都能够获得要传送的EPR态。方案的第一步是采用部分纠缠态作为量子信道去实现EPR态的隐形传态。根据量子不可克隆定理，输入态在发送方受到破坏。方案的第二步通过引入一个辅助量子位，发送者Alice在态的配制者Victor的帮助下，将以联合概率成功地获得未知EPR态和它的正交态。从而实现了量子态的重建。

Probabilistic Copying and OrthogonalComplementing of an Unknown EPR State

Entangled states play an important role in quantum computation and quantum information. A partially entangled state is applied to be a resource and it is proposed a scheme where one can successfully realize copying and orthogonal complementing of an unknown EPR (Einstein-Podolsky-Rosen) pair in a certain probability so that two parties of communication can obtain the EPR state. The first stage of this scheme is to apply a quantum channel, that is a partially entangled channel of three-particle, to teleport an unknown EPR state. Based on the no-cloning theorem, the input state will be destructed at the place of sender in teleportation. In the second stage, through introducing an auxiliary qubit, Alice(a sender) can achieve a copy or an orthogonal-complement copy of the EPR pair with assistance of Victor(a state preparer) in a unite probability. Reestablishment of quantum state is realized in the scheme.