Hardy’s nonlocality argument as a witness for postquantum correlations

摘要

Recently, Gallego et al. [Phys. Rev. Lett. 107, 210403 (2011)] proved that any future information principlenaiming at distinguishing between quantum and postquantum correlation must be intrinsically multipartite innnature. We establish similar results by using the device-independent success probability of Hardy’s nonlocalitynargument for tripartite quantum systems. We construct an example of a tripartite Hardy correlation which isnpostquantum but satisfies not only the all-bipartite information principle but also the guess-your-neighbor’s-inputn(GYNI) inequality.