Characterization of Nonlocality in Chained Quantum Networks

Quantum information processing shows its superiority and particularity over classical information processing. One of the main characteristics that distinguishes quantum network from classical network is its nonlocality. The characterization and quantification of quantum nonlocality is the core task of quantum information and has great significance. In this paper, we study the nonlocality of a chain quantum network with three sources and four participants, construct a 3-local Bell inequality, and prove its quantum violation. Our results will promote the construction efficiency of Bell inequalities and contribute theoretical significance for quantum non-locality.