Entanglement-assisted guessing of complementary measurement outcomes

Entanglement-assisted guessing of complementary measurement outcomes

Berta, M.
Coles, P.J.
Wehner, S.D.C.

Electrical Engineering, Mathematics and Computer Science

Intelligent Systems

2014-12-22

Heisenberg's uncertainty principle implies that if one party (Alice) prepares a system and randomly measures one of two incompatible observables, then another party (Bob) cannot perfectly predict the measurement outcomes. This implication assumes that Bob does not possess an additional system that is entangled to the measured one; indeed, the seminal paper of Einstein, Podolsky, and Rosen (EPR) showed that maximal entanglement allows Bob to perfectly win this guessing game. Although not in contradiction, the observations made by EPR and Heisenberg illustrate two extreme cases of the interplay between entanglement and uncertainty. On the one hand, no entanglement means that Bob's predictions must display some uncertainty. Yet on the other hand, maximal entanglement means that there is no more uncertainty at all. Here we follow an operational approach and give an exact relation—an equality—between the amount of uncertainty as measured by the guessing probability and the amount of entanglement as measured by the recoverable entanglement fidelity. From this equality, we deduce a simple criterion for witnessing bipartite entanglement and an entanglement monogamy equality.

http://resolver.tudelft.nl/uuid:29ac7b63-26e5-4f8b-8f64-99425eb7a542

https://doi.org/10.1103/PhysRevA.90.062127

American Physical Society

1050-2947

http://journals.aps.org/pra/abstract/10.1103/PhysRevA.90.062127

Physical Review A, 90 (6), 2014

Institutional Repository

journal article

© 2014 American Physical Society