Nonlocality in Quantum Network

In this section, we present the nonlocality Bell (1964) in quantum network scenarios. There are at least two motivations for extending the nonlocality in networks. One is similar to Bell’s theorem that aims to understand quantum theory and its relationship to other models. The other is from applications of quantum information. There is increasing interest in quantum networks because of their flexibility and efficiency in various tasks. Bell nonlocality in networks may bring novel forms of quantumness. When many independent entangled states are distributed in a network, some parties distribute entanglement among distant, initially independent systems for space-separate parties with the help of local measurements.