Group of Applied Physics, Université de Genève, 1211 Genève, Switzerland.
Institut Néel, CNRS and Université Grenoble Alpes, 38042 Grenoble Cedex 9, France.
Phys Rev Lett. 2016 Jan 8;116(1):010403. doi: 10.1103/PhysRevLett.116.010403. Epub 2016 Jan 7.
In a quantum network, distant observers sharing physical resources emitted by independent sources can establish strong correlations, which defy any classical explanation in terms of local variables. We discuss the characterization of nonlocal correlations in such a situation, when compared to those that can be generated in networks distributing independent local variables. We present an iterative procedure for constructing Bell inequalities tailored for networks: starting from a given network, and a corresponding Bell inequality, our technique provides new Bell inequalities for a more complex network, involving one additional source and one additional observer. We illustrate the relevance of our method on a variety of networks, demonstrating significant quantum violations, which could not have been detected using standard Bell inequalities.
在量子网络中，共享独立源发出的物理资源的远距离观察者可以建立强关联，这使得任何基于局部变量的经典解释都变得不可能。我们讨论了在这种情况下，与可以在分布独立局部变量的网络中产生的关联相比，非局部关联的特征。我们提出了一种用于构建针对网络的贝尔不等式的迭代过程：从给定的网络和相应的贝尔不等式开始，我们的技术为涉及一个额外源和一个额外观察者的更复杂网络提供了新的贝尔不等式。我们在各种网络上说明了我们方法的相关性，展示了显著的量子违反，这些违反是无法使用标准贝尔不等式检测到的。
