Unidirectional Gaussian One‐Way Steering

Abstract

AbstractSteering is a type of quantum nonlocality that exhibits an inherent asymmetry between two observers. In a nondegenerate three‐level laser coupled to a two‐mode squeezed vacuum reservoir, under realistic experimental conditions, the Gaussian steering of two laser modes, and , generated within the cascade transitions, respectively are examined. It is found that the steerability is always higher than that from ; in addition, the steering asymmetry cannot exceed ln 2, which implies that the state never diverges to an extremal asymmetry state. It is shown how squeezed noise can play a constructive role in realizing one‐way steering. As the main result, it is demonstrated that the state can exhibit one‐way steering solely from , which is shown to emerge as a consequence of the fact that the intensity difference of the modes and is verified to remain always positive, irrespective of the physical and environmental parameters of . The generated unidirectional one‐way steering may provide a useful resource for the distribution of the trust in future asymmetric quantum information tasks.