Nontrilocality: Exploiting nonlocality from three-particle systems

Branciard et al. [Phys. Rev. Lett. 104, 170401 (2010)] first characterized the correlations arising in an entanglement swapping network under the assumption that the sources generating the initially uncorrelated quantum systems are independent. Precisely speaking, Branciard et al. [Phys. Rev. Lett. 104, 170401 (2010) and later in Phys. Rev. A 85, 032119 (2012)] analyzed the importance of bilocal (source independence) assumption to lower the restrictions over correlations for revealing quantumness in the network where each of two sources generates a bipartite entangled state. In this context, one may find interest to characterize correlations in a network involving independent sources which can correlate more than two initially uncorrelated multipartite entangled quantum systems. Our present topic of discussion basically analyzes such a network scenario. Specifically, we introduce a trilocal network scenario where each of three sources independently generates a tripartite entangled quantum system, thereby exploring the role of source independence assumption to exploit nonlocality in a network involving multipartite entanglement analogous to bilocal assumption in a network where only bipartite entanglement was considered. Interestingly, genuine entanglement content did not turn out to be an essential requirement for exploiting nonlocality in such a scenario. Moreover, it is interesting to explore whether such a scenario can be generalized so as to characterize correlations arising in a network involving n number of n-partite systems for any finite value of n >= 4 under source independence assumption.