Abstract
Within the hierarchy of inseparable quantum correlations, Einstein-Podolsky-Rosen steering is distinguished from both entanglement and Bell nonlocality by its asymmetry—there exist conditions where the steering phenomenon changes from being observable to not observable, simply by exchanging the role of the two measuring parties. While this one-way steering feature has been previously demonstrated for the restricted class of Gaussian measurements, for the general case of positive-operator-valued measures even its theoretical existence has only recently been settled. Here, we prove, and then experimentally observe, the one-way steerability of an experimentally practical class of entangled states in this general setting. As well as its foundational significance, the demonstration of fundamentally asymmetric nonlocality also has practical implications for the distribution of the trust in quantum communication networks.
- Received 3 November 2015
DOI:https://doi.org/10.1103/PhysRevLett.116.160403
© 2016 American Physical Society
Physics Subject Headings (PhySH)
Synopsis
One-Way Quantumness
Published 21 April 2016
Experiments provide evidence for one-way quantum steering—an effect by which distant entangled systems can influence one another in a directional way.
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