Witnessing network steerability of every bipartite entangled state without inputs

Abstract

Quantum steering is an asymmetric form of quantum nonlocality where one can detect whether a measurement on one system can steer or change another distant system. It is well-known that there are quantum states that are entangled but unsteerable in the standard quantum steering scenario. Consequently, a long-standing open problem in this regard is whether the steerability of every entangled state can be activated in some way. In this work, we consider quantum networks and focus on the swap-steering scenario without inputs and find linear witnesses of network steerability corresponding to any negative partial transpose (NPT) bipartite state and a large class of bipartite states that violate the computable cross-norm (CCN) criterion. Furthermore, by considering that the trusted party can perform tomography of the incoming subsystems, we construct linear inequalities to witness swap-steerability of every bipartite entangled state. Consequently, for every bipartite entangled state one can now observe a form of quantum steering.

8 pages, 1 figure, Comments are welcome!

References in corpus (9)

• Entanglement detection
• Steering, Entanglement, Nonlocality, and the EPR Paradox
• Network Quantum Steering
• Super-Activation of Quantum Steering
• Self-testing of any pure entangled state with minimal number of measurements and optimal randomness certification in one-sided device-independent scenario
• Certification of incompatible measurements using quantum steering
• Certification of the maximally entangled state using non-projective measurements
• Network quantum steering enables randomness certification without seed randomness
• Topologically noise robust network steering without inputs

Cited by in corpus (1)

• Network quantum steering enables randomness certification without seed randomness