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arXiv 1010.0900quant-ph
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量子网络揭示量子非局域性

Quantum networks reveal quantum nonlocality

D. Cavalcanti, M. L. Almeida, V. Scarani, A. Acin

摘要:

某些复合量子系统的局域测量结果不能经典地再现。这种不可能性,被称为量子非定域性,代表了量子理论基础上的一个里程碑。量子非定域性也是信息处理任务的宝贵资源,例如量子通信、量子密钥分发、量子态估计或随机性提取。然而,决定一个量子态是否是非定域的仍然是一个具有挑战性的问题。在这里,我们介绍了一个新的方法来解决这个问题:我们研究的量子态的非局域特性时,分布和测量的网络。使用我们的框架,我们展示了如何任何单向纠缠可压缩状态导致非本地相关。然后,我们证明了非局部性是一种非加性资源,它可以被激活。在单拷贝水平上,存在着局域态,当取多个拷贝时,这些局域态就变成非局域态。我们的结果表明,量子态的非局域性强烈地依赖于测量上下文。

英文摘要:

The results of local measurements on some composite quantum systems cannot be reproduced classically. This impossibility, known as quantum nonlocality, represents a milestone in the foundations of quantum theory. Quantum nonlocality is also a valuable resource for information processing tasks, e.g. quantum communication, quantum key distribution, quantum state estimation, or randomness extraction. Still, deciding if a quantum state is nonlocal remains a challenging problem. Here we introduce a novel approach to this question: we study the nonlocal properties of quantum states when distributed and measured in networks. Using our framework, we show how any one-way entanglement distillable state leads to nonlocal correlations. Then, we prove that nonlocality is a non-additive resource, which can be activated. There exist states, local at the single-copy level, that become nonlocal when taking several copies of it. Our results imply that the nonlocality of quantum states strongly depends on the measurement context.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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