Abstract
We present a loophole-free violation of local realism using entangled photon pairs. We ensure that all relevant events in our Bell test are spacelike separated by placing the parties far enough apart and by using fast random number generators and high-speed polarization measurements. A high-quality polarization-entangled source of photons, combined with high-efficiency, low-noise, single-photon detectors, allows us to make measurements without requiring any fair-sampling assumptions. Using a hypothesis test, we compute values as small as for our Bell violation while maintaining the spacelike separation of our events. We estimate the degree to which a local realistic system could predict our measurement choices. Accounting for this predictability, our smallest adjusted value is . We therefore reject the hypothesis that local realism governs our experiment.
- Received 10 November 2015
DOI:https://doi.org/10.1103/PhysRevLett.115.250402
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Published by the American Physical Society
- *This work includes contributions of the National Institute of Standards and Technology, which are not subject to U.S. copyright.
Physics Subject Headings (PhySH)
Viewpoint
Closing the Door on Einstein and Bohr’s Quantum Debate
Published 16 December 2015
By closing two loopholes at once, three experimental tests of Bell’s inequalities remove the last doubts that we should renounce local realism. They also open the door to new quantum information technologies.
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