Unified criteria for multipartite quantum nonlocality

Abstract

Wiseman and co-workers [ H. M. Wiseman, S. J. Jones and A. C. Doherty Phys. Rev. Lett. 98 140402 (2007)] proposed a distinction among the nonlocality classes of Bell's nonlocality, Einstein-Podolsky-Rosen (EPR) paradox or steering, and entanglement based on whether or not an overseer trusts each party in a bipartite scenario where they are asked to demonstrate entanglement. Here we extend that concept to the multipartite case and derive inequalities that progressively test for those classes of nonlocality, with different thresholds for each level. This framework includes the three classes of nonlocality above in special cases and introduces a family of others.