An Economical Scheme for Cloning an Unknown M-Qudit Equatorial-Like State with Assistance

我们建议认识到量克隆未知 M-qudit 象赤道一样的一个计划纠缠了状态。协议的第一个阶段要求远距传物。在远距传物被完成以后，接收装置能重建原来的状态。在协议的第二个阶段，与帮助(通过单个粒子的射影的大小) preparer，一个原来的状态的完美的拷贝能在发送者的地点被生产。我们的计划作为量隧道和三摩尔斯讯号的短音要求单个最大地纠缠的 qudit 对古典通讯。计划在损坏消费包括 M 的本地资源的情况下是可行的 ? 1 辅助 qudits 由接收装置和另外的 bi-qudit 操作介绍了。而且，我们构造保证辅助 qudits 被发送者未必介绍的一种单一的转变。比作以前的协议，建议协议是节俭的由于量的费用非局部的资源和古典通讯最低。

We propose a scheme to realize quantum cloning of an unknown M-qudit equatorial-like entangled state. The first stage of the protocol requires teleportation. After the teleportation is accomplished, the receiver can reestablish the original state. In the second stage of the protocol, with the assistance （through a single-particle projective measurement） of the preparer, the perfect copy of an original state can be produced at the site of the sender. Our scheme requires a single maximally entangled qudit pair as the quantum channel and three dits classical communication. The scheme is feasible at the expense of consuming local resources which include M - 1 ancillary qudits introduced by the receiver and additional bi-qudit operations. Moreover, we construct a sort of unitary transformations which ensure ancillary qudits are not necessarily introduced by the sender. Comparing to the previous protocols, the proposed protocol is economical due to that the cost of both quantum nonlocal resources and classical communication is lowest.