an:05991844
Zbl 1228.81078
Wiseman, H. M.; Jones, S. J.; Doherty, A. C.
Steering, entanglement, nonlocality, and the Einstein-Podolsky-Rosen paradox
EN
Phys. Rev. Lett. 98, No. 14, Article ID 140402, 4 p. (2007).
00292510
2007
j
81P15 81P40
Summary: The concept of steering was introduced by Schr??dinger in 1935 as a generalization of the Einstein-Podolsky-Rosen paradox for arbitrary pure bipartite entangled states and arbitrary measurements by one party. Until now, it has never been rigorously defined, so it has not been known (for example) what mixed states are steerable (that is, can be used to exhibit steering). We provide an operational definition, from which we prove (by considering Werner states and isotropic states) that steerable states form a strict subset of the entangled states, and a strict superset of the states that can exhibit Bell nonlocality. For arbitrary bipartite Gaussian states we derive a linear matrix inequality that decides the question of steerability via Gaussian measurements, and we relate this to the original Einstein-Podolsky-Rosen paradox.