Nonlocal correlations in the tree-tensor-network configuration

The process of entanglement swapping showed that suitable measurements can generate nonlocal correlations even from particles that never interacted directly. This fact was generalized to the concept of bilocality for a quantum network, where there are three observers sharing two independent sources. Since then, the nonlocality nature was explored in various quantum networks. In this work, we consider the nonlocality of (2(n) - 1)-partite tree-tensor networks, which are widely used in quantum communications. We derive the Bell-type inequalities which are respectively satisfied by all (2(n) - 2)-local correlations and all local correlations, and demonstrate the maximal quantum violations of these inequalities and the robustness to noise in these tree networks.

Automated summary

In this work, the nonlocality of (2(n) - 1)-partite tree-tensor networks used in quantum communications is considered. Bell-type inequalities are derived which are satisfied by all (2(n) - 2)-local correlations and all local correlations, showcasing the maximal quantum violations of these inequalities and their robustness to noise in these tree networks.