用三粒子纠缠态作量子信道远程操纵单比特旋转

提出用三粒子纠缠态作量子信道远程操纵单比特旋转的理论方案。首先，我们利用最大纠缠的GHZ态的性质远程操纵单比特旋转，其保真度和成功几率均为1。 我们还提出了两个用部分纠缠的GHZ态作量子信道实现保真度为1的远程操纵单比特旋转的方案。这些方案的特点是，两地之间还存在一第三者，他作为监控方参与量子远程操纵过程，特别地，当量子信道为部分纠缠态时，他能矫正被非理想量子信道致畸的量子态。除了GHZ型态外，我们还证明了W型态亦可用作量子信道远程操纵单比特旋转，但后者的成功几率总是小于前者。

Implementing remotely a single-qubit rotation operation by three-qubit entanglement

We investigate the problem of quantum remote implementation of a single-qubit rotation operation using three-qubit entangled state. Firstly,we utilize the entanglement property of maximally entangled Greenberger--Horne--Zeilinger (GHZ) state to design a theoretical scheme for implementing the operation remotely with unit fidelity and unit probability. Then, we put forward two schemes for conclusive implementing the non-local single-qubit rotation with unit fidelity by employing a partially entangled pure GHZ state as quantum channel. The features of these schemes are that a third side is included,who may participate the process of quantum remote implementation as a supervisor. Furthermore, when the quantum channel is partially entangled,the third side can rectify the state distorted by imperfect quantum channel.In addition to the GHZ class state, the $W$ class state can also be used to remotely implement the same operation probabilistically. The probability of successful implementation using the $W$ class state is always less than that using the GHZ class state.