Tractable protocol for detection-loophole-free bell tests over long distances
File(s)xw66-nqfs.pdf (1.48 MB)
Published version
Author(s)
Type
Journal Article
Abstract
Certifying genuine nonclassical correlations over long distances is essential for device-independent quantum information. In photonic platforms, however, this remains challenging due to photon loss, which opens the detection loophole, rendering violations increasingly difficult for less-efficient detectors. Eberhard showed that using nonmaximally entangled states lowers the detection-efficiency threshold to 66.7%, but existing photonic approaches are restricted to short distances with linear transmittance scaling. Conversely, single-photon event-ready schemes extend the distance with favorable square-root scaling with channel transmittance, yet still demand detection efficiencies above 82.6%. Here, we propose the first all-photonic, heralded entanglement distribution protocol that unifies these two advances: It achieves a postselection-free violation at the Eberhard limit while preserving twin-field-like scaling. We identify the loss independent of the vacuum component amplitude of the prepared state as the source of this enhancement. Our approach addresses both resilience to loss and scalability, providing a practical route toward long-distance, loophole-free Bell tests and device-independent applications with current technology.
Date Issued
2025-11-20
Date Acceptance
2025-10-21
Citation
Physical Review Research, 2025, 7 (4)
ISSN
2643-1564
Publisher
American Physical Society
Journal / Book Title
Physical Review Research
Volume
7
Issue
4
Copyright Statement
© The Author(s) 2025. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
License URL
Identifier
10.1103/xw66-nqfs
Publication Status
Published
Article Number
043198