Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

The Rochester Conferences on Coherence and Quantum Optics and the Quantum Information and Measurement meeting

The End of Local Realism…ish

B. Christensen, Kevin McCusker, Joseph B. Altepeter, Brice Calkins, Thomas Gerrits, Adriana E. Lita, Aaron Miller, Lynden K. Shalm, Sae Woo Nam, Nicolas Brunner, Paul G. Kwiat

Published Jan 1, 2013• 0 citations
Publisher

Abstract

Using a high-quality source of non-maximal polarization entanglement, optimized filters and collection optics, and ultra-high efficiency photon counters, we have performed what we believe is the first truly detection-loophole-free test of nonlocality with photons.
DOI
10.1364/qim.2013.th3.1

Related papers

Test of quantum nonlocality by full collection of polarization entangled photon pairs

Marco Barbieri, C. Cinelli, F. De Martini +1 more

The European Physical Journal D•Jan 4, 2005•13 citations

Detection-Loophole-Free Test of Quantum Nonlocality, and Applications

Bradley Christensen, Kevin T. McCusker, Joseph B. Altepeter +11 more

We present a source of entangled photons that violates a Bell inequality free of the "fair-sampling" assumption, by over 7 standard deviations. This violation is the first reported experiment with photons to close the detection loophole, and we demonstrate enough "efficiency" overhead to eventually perform a fully loophole-free test of local realism. The entanglement quality is verified by maximally violating additional Bell tests, testing the upper limit of quantum correlations. Finally, we use the source to generate "device-independent" private quantum random numbers at rates over 4 orders of magnitude beyond previous experiments.

arXiv:1306.5772•Physical Review Letters•Sep 26, 2013•477 citations

Statistical strength of experiments to reject local realism with photon pairs and inefficient detectors

Yanbao Zhang, Emanuel H. Knill, Scott Glancy

Because of the fundamental importance of Bell's theorem, a loophole-free demonstration of a violation of local realism (LR) is highly desirable. Here, we study violations of LR involving photon pairs. We quantify the experimental evidence against LR by using measures of statistical strength related to the Kullback-Leibler (KL) divergence, as suggested by van Dam et al. [W. van Dam, R. D. Gill, and P. D. Grunwald, IEEE Trans. Inf. Theory. 51, 2812 (2005)]. Specifically, we analyze a test of LR with entangled states created from two independent polarized photons passing through a polarizing beam splitter. We numerically study the detection efficiency required to achieve a specified statistical strength for the rejection of LR depending on whether photon counters or detectors are used. Based on our results, we find that a test of LR free of the detection loophole requires photon counters with efficiencies of at least $89.71%$, or photon detectors with efficiencies of at least $91.11%$. For comparison, we also perform this analysis with ideal unbalanced Bell states, which are known to allow rejection of LR with detector efficiencies above $2/3$.

arXiv:1001.1750•Physical Review A•Mar 18, 2010•16 citations

Various Quantum Nonlocality Tests with a Commercial Two-photon Entanglement Source

Jean-Daniel Bancal

Springer theses•Nov 22, 2013•0 citations

Loophole-Free Test of Quantum Nonlocality and Efficient Noiseless Amplification for Large Optical Fields

Jinwoo Park

•Jan 1, 2015•0 citations

Strong Loophole-Free Test of Local Realism

Lynden K. Shalm, Evan Meyer-Scott, Bradley Christensen +31 more

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 p values as small as 5.9×10^{-9} 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 p value is 2.3×10^{-7}. We therefore reject the hypothesis that local realism governs our experiment.

arXiv:1511.03189•Physical Review Letters•Dec 16, 2015•1,400 citations
We present a source of entangled photons that violates a Bell inequality free of the "fair-sampling" assumption, by over 7 standard deviations. This violation is the first reported experiment with photons to close the detection loophole, and we demonstrate enough "efficiency" overhead to eventually perform a fully loophole-free test of local realism. The entanglement quality is verified by maximally violating additional Bell tests, testing the upper limit of quantum correlations. Finally, we use the source to generate "device-independent" private quantum random numbers at rates over 4 orders of magnitude beyond previous experiments.
Because of the fundamental importance of Bell's theorem, a loophole-free demonstration of a violation of local realism (LR) is highly desirable. Here, we study violations of LR involving photon pairs. We quantify the experimental evidence against LR by using measures of statistical strength related to the Kullback-Leibler (KL) divergence, as suggested by van Dam et al. [W. van Dam, R. D. Gill, and P. D. Grunwald, IEEE Trans. Inf. Theory. 51, 2812 (2005)]. Specifically, we analyze a test of LR with entangled states created from two independent polarized photons passing through a polarizing beam splitter. We numerically study the detection efficiency required to achieve a specified statistical strength for the rejection of LR depending on whether photon counters or detectors are used. Based on our results, we find that a test of LR free of the detection loophole requires photon counters with efficiencies of at least 89.7189.71%89.71, or photon detectors with efficiencies of at least 91.1191.11%91.11. For comparison, we also perform this analysis with ideal unbalanced Bell states, which are known to allow rejection of LR with detector efficiencies above 2/32/32/3.
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 p values as small as 5.9×10^{-9} 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 p value is 2.3×10^{-7}. We therefore reject the hypothesis that local realism governs our experiment.