Superactivation of Multipartite Unlockable Bound Entanglement
Superactivation of Multipartite Unlockable Bound Entanglement
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多部分可解锁束缚纠缠的超激活
DOI：
10.1103/physrevlett.108.190501
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发表时间：
2012-05-09
影响因子：
8.6
通讯作者：
Peng, Kunchi
中科院分区：
文献类型：
--
作者：
Jia, Xiaojun;Zhang, Jing;Peng, Kunchi
多体束缚纠缠（BE）的超激活是Shor等人在2003年提出的一种特殊的协议，它可以在两个多体BE态的两个子系统之间提取Einstein-Podolsky-罗森（EPR）纠缠态。在这里，我们提出了第一个实验实现的超激活的BE状态，其中使用两个副本的四分解锁BE状态在连续变量制度。在两个50-50分束器上，将两个带有高斯噪声的热态分别耦合到EPR纠缠态的两个子模中，输出的四个光模形成一个四分可解锁的BE态。利用两个EPR纠缠态，我们首先在实验上产生了两个BE态。然后通过对两个BE态的测量和反馈的超激活操作，在两个四体BE态的两个指定方之间提取出EPR纠缠态。实验证明了量子纠缠的超可加性，因为单个BE态不能被提取，只能提取两个BE态。
The superactivation of multipartite bound entanglement (BE) is a special protocol proposed by Shor et al. in 2003, which can distill Einstein-Podolsky-Rosen (EPR) entanglement states between two subsystems of two multipartite BE states. Here we present the first experimental realization of the superactivation of the BE state, in which two copies of the four-partite unlockable BE state in a continuous-variable regime are used. Coupling two thermal states with Gaussian noises into two submodes of an EPR entangled state on two 50-50 beam splitters respectively, the four output optical modes form a four-partite unlocklable BE state. Using two EPR entangled states, we experimentally produce two BE states first. Then through a superactivation operation involving measurements and feedback on the two BE states, an EPR entangled state is distilled out between two designated parties of the two four-partite BE states. The experiment demonstrates the superadditivity of quantum entanglement as the individual BE state cannot be distilled, only two BE states together can be distilled.