论文标题
在量子网络中回收非局部性
Recycling nonlocality in a quantum network
论文作者
论文摘要
最近发现，可以将纠缠量子对的非销售性回收用于多个钟形实验。在这里，我们超越了标准的铃铛场景，并研究了量子网络中非本地资源的回收利用。我们实现了一个光子量子3分支星星网络，其中三个纠缠对来源将三个外部各方与中央节点独立连接。测量之后，每个外部方分别将其系统传递给一个独立的次要测量方。我们在实验上证明，外部各方可以执行较高的测量值，这些测量足以违反与中央党的网络铃铛不平等，但足够弱，可以在网络中保持足够的纠缠，以使三个次要方都可以做同样的事情。此外，这些违规行为足以根据网络中发出的EPR对的标准投影测量值排除任何模型。我们的实验将回收量子资源的研究计划与网络中的贝尔非局部性汇总在一起。
It has recently been discovered that the nonlocality of an entangled qubit pair can be recycled for several Bell experiments. Here, we go beyond standard Bell scenarios and investigate the recycling of nonlocal resources in a quantum network. We realise a photonic quantum 3-branch star network in which three sources of entangled pairs independently connect three outer parties with a central node. After measuring, each outer party respectively relays their system to an independent secondary measuring party. We experimentally demonstrate that the outer parties can perform unsharp measurements that are strong enough to violate a network Bell inequality with the central party, but weak enough to maintain sufficient entanglement in the network to allow the three secondary parties to do the same. Moreover, the violations are strong enough to exclude any model based on standard projective measurements on the EPR pairs emitted in the network. Our experiment brings together the research program of recycling quantum resources with that of Bell nonlocality in networks.
