Abstract
Einstein-Podolsky-Rosen (EPR) steering describes the ability of one observer to nonlocally “steer” the other observer’s state through local measurements. EPR steering exhibits a unique asymmetric property; i.e., the steerability can differ between observers, which can lead to one-way EPR steering in which only one observer obtains steerability in the steering process. This property is inherently different from the symmetric concepts of entanglement and Bell nonlocality, and it has attracted increasing interest. Here, we experimentally demonstrate asymmetric EPR steering for a class of two-qubit states in the case of two measurement settings. We propose a practical method to quantify the steerability. We then provide a necessary and sufficient condition for EPR steering and clearly demonstrate one-way EPR steering. Our work provides new insight into the fundamental asymmetry of quantum nonlocality and has potential applications in asymmetric quantum information processing.
- Received 16 February 2016
DOI:https://doi.org/10.1103/PhysRevLett.116.160404
© 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.
See more in Physics