Genuine Multipartite Nonlocality for All Isolated Many-body Systems

Abstract: Understanding the nonlocality of many-body systems offers valuable insights into the behaviors of these systems and may have practical applications in quantum simulation and quantum computing. Gisin's Theorem establishes the equivalence of three types of quantum correlations: Bell nonlocality, EPR-steering, and entanglement for isolated systems. No similar result exists with regard to genuine multipartite correlations. We answer this open problem by proposing a new network-inflation method. Our approach demonstrates that genuine multipartite nonlocality, genuine multipartite EPR-steering, and genuine multipartite entanglement are equivalent for any isolated many-body system. This is achieved through an extended Bell test on an inflated network consisting of multiple copies of the given sources. The device-independent method is also robust against noise.