Concentrating partial entanglement by local operations
Concentrating partial entanglement by local operations
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DOI：
10.1103/physreva.53.2046
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发表时间：
1996-04-01
影响因子：
2.9
通讯作者：
Schumacher, B
中科院分区：
文献类型：
--
作者：
Bennett, CH;Bernstein, HJ;Schumacher, B
如果两个分离的观察者被提供纠缠，以n对处于相同的部分纠缠纯态的粒子的形式，每对中的一个成员被给予每个观察者，他们可以通过每个观察者的局部作用将这种纠缠集中到更少数量的最大纠缠粒子对中，例如，爱因斯坦-波多尔斯基-罗森单线态，类似地在两个观察者之间共享。浓度过程渐近保守熵的纠缠-冯诺依曼熵的偏密度矩阵看到的任何一个双态-与产量的单态接近，对于大n，基2纠缠的初始部分纠缠纯态的熵。相反，两个系统的任何纯纠缠态或混合纠缠态都可以由两个经典通信的分离观察者产生，并将单线态作为其唯一的纠缠源。
If two separated observers are supplied with entanglement, in the form of n pairs of particles in identical partly entangled pure states, one member of each pair being given to each observer, they can, by local actions of each observer, concentrate this entanglement into a smaller number of maximally entangled pairs of particles, for example, Einstein-Podolsky-Rosen singlets, similarly shared between the two observers. The concentration process asymptotically conserves entropy of entanglement-the von Neumann entropy of the partial density matrix seen by either observer-with the yield of singlets approaching, for large n, the base-2 entropy of entanglement of the initial partly entangled pure state. Conversely, any pure or mixed entangled state of two systems can be produced by two classically communicating separated observers, drawing on a supply of singlets as their sole source of entanglement.