量子纠缠态的普适远程克隆

提出一种任意两粒子纠缠态1→2普适远程克隆方案. 此方案仅需一个特殊的四粒子纠缠态作为量子信道, 就可使处于空间不同位置的两个接收者分别以5/6的保真度得到任意输入态的近似拷贝, 该保真度远高于已有方案中的保真度. 将方案推广到任意两粒子纠缠态1→N(N>2)普适远程克隆的情况, 可使处于不同地点的N个接收者分别以(2N+1)/(3N)的保真度得到输入态的近似拷贝. 另外, 提出一种以上述单个特殊四粒子纠缠态作为量子信道, 在多目标量子比特受控非门和关键词：量子纠缠态普适远程克隆保真度

Universal telecloning of quantum entangled states

A scheme for 1→2 universal telecloning of an arbitrary two-particle entangled state using a single, particular four-particle entangled state as quantum information channel is proposed. The spatially separated two receivers respectively receive one copy of the original unknown state with the fidelity of 5/6 which isindependent of the original state and is greater than the one in the currently existing schemes.Our scheme has been generalized to the case of 1→N(N>2) universal telecloning of an arbitrary two-particle entangled state. Using this scheme, the spatially separated N receivers respectively obtain one copy with the fidelity of (2N+1)/(3N) which is independent of the original state. Furthermore, we also proposed a scheme using the same four-particle entangled state as quantum information channel with the assistance of multi-target-qubit Control-Not gate and additional qubits, for 1→2 universal telecloning of an arbitrary n-particle(n≥3) Greenberger-Horne-Zeilinger (GHZ) state. This scheme is also generalized into the situation of 1→N(N>2) telecloning of an arbitrary n-particle GHZ state. Compared with previous proposals, our schemes require a reduced amount of entangled states as quantum channels to accomplish the task of universal telecloning of entangled state with better fidelity.