Abstract: A perfect protocol is put forward for implementation of nonlocal Bell-state measurement by using pre-shared maximally entangled pair and Local Operations as well as Classical Communication（LOCC）, then it is generalized by using partially entangled channel instead of maximally entangled channel, and shows that the nonlocal Bell-state measurement can be performed probabilistically by introducing a unitary transformation, and the generalized scheme can be regarded as a purification scheme. Subsequently, this paper discusses the required resources for these protocols and reveals the experimental feasibility of the schemes with the current technologies. In addition, the protocols can be used to generate some new maximally quantum entangled states.

Key words: nonlocal Bell-state measurement, maximally entangled pair, partially entangled pair, unitary transformation, purification

摘要： 利用预先分享的最大纠缠对、局域操作和经典通信，提出了执行非局域Bell-态测量的一个完美方案。通过用部分纠缠信道取代最大纠缠信道，推广了上述方案，指出采用酉变换就能概率地施行非局域Bell-态测量，并且推广方案可视为一个提纯方案。讨论了这些协议所需的资源，并说明了这些方案在现有技术下的实验实现是可行的。此外，该协议可以用来生成一些新的最大量子纠缠态。

关键词: 非局域Bell-态测量, 最大纠缠对, 部分纠缠对, 酉变换, 提纯