多方控制量子通信协议

Multi-party controlled quantum communication protocol

为了满足远距离多节点量子网络的需求,分别利用最大纠缠信道和部分纠缠信道构造了2个多方控制量子通信协议。最大纠缠信道时,利用投影测量实现多方控制四粒子χ-态远程制备;部分纠缠信道时,利用联合酉操作和最优POVM实现多方控制四粒子χ-态远程制备。理论推导表明,第一个协议的效率达到100%且优于其他协议,第二协议的效率被有效提高且2种测量方法的构造方法可被用于同类协议。

In order to satisfy the requirements of long-distance multi-node quantum networks,two multi-party controlledquantum communication protocols are put forward via maximally and partially entangled quantum channels. For the maximally entangled channels, projective measurements are used to realizemulti-party controlled joint remote preparation of an arbitrary four-qubitχ-state. For the partially entangled channels, collective unitary operations and optimal positive operator-valued measures are used to realize multi-party controlled joint remote preparation of an arbitrary four-qubitχ-state.The theoretical analysis shows that the efficiency of the first scheme can be up to 100% which is suprior to that of others. In addition, the efficiency of the second scheme is effectively improved and the way to be used to construct two kinds of measurement methods can be utilized in the similar protocols.