Multipartite nonlocality in an Ising model with a tilted magnetic field at zero and finite temperatures

Abstract

We use the multipartite nonlocality to detect the quantum phase transitions (QPTs) in the one-dimensional Ising model with a tilted magnetic field. For a given transverse magnetic field, we investigate the impact of the coupling strength, the longitudinal magnetic field, and the temperature on the multipartite nonlocality and its first derivative. We show that both the multipartite nonlocality and its first derivative of the ground-state can perfectly characterize the QPTs of the model. We further show that the multipartite nonlocality at finite temperature exhibits different behavior from that of the ground-state. We find that the thermal fluctuations can weaken the multipartite nonlocality. However, a high longitudinal magnetic field can destroy the weakening effect of the thermal fluctuations, particularly near the QPTs point. In particular, we find that the logarithm measure of multipartite nonlocality both at zero and finite temperature shows a linear behavior for any fixed longitudinal magnetic field.