Locking and unlocking nonlocality without entanglement by post-measurement information - Jeong San Kim

Nonlocality without entanglement(NLWE) is a nonlocal quantum phenomenon that arises in separable state discrimination. In this talk, we consider the situation of discriminating quantum states from an ensemble of non-orthogonal separable states, and show that the availability of the post-measurement information about the prepared subensemble can affect the occurrence of NLWE. We provide a class of state ensembles consisting of four non-orthogonal separable pure states and show that the post-measurement information about the prepared subensemble can lock(annihilate) NLWE. We also provide another class of separable state ensemble and show that the post-measurement information can unlock(create) NLWE.
Reference
[1] Donghoon Ha and Jeong San Kim, "Annihilating and creating nonlocality without entanglement by postmeasurement information", Phys. Rev. A, 105, 022422 (2022).
[2] Donghoon Ha and Jeong San Kim, "Locking and unlocking of quantum nonlocality without entanglement in local discrimination of quantum states", Scientific Reports, 12, 3961 (2022).