Sub-shot-noise transmission measurement enabled by active feed-forward of heralded single photons

Sabines-Chesterking, J., Whittaker, R., Joshi, S.K., Birchall, P.M., Moreau, P.-A. , McMillan, A., Cable, H.V., O’Brien, J.L., Rarity, J.G. and Matthews, J.C.F. (2017) Sub-shot-noise transmission measurement enabled by active feed-forward of heralded single photons. Physical Review Applied, 8(1), 014016. (doi: 10.1103/PhysRevApplied.8.014016)

Abstract

Harnessing the unique properties of quantum mechanics offers the possibility of delivering alternative technologies that can fundamentally outperform their classical counterparts. These technologies deliver advantages only when components operate with performance beyond specific thresholds. For optical quantum metrology, the biggest challenge that impacts on performance thresholds is optical loss. Here, we demonstrate how including an optical delay and an optical switch in a feed-forward configuration with a stable and efficient correlated photon-pair source reduces the detector efficiency required to enable quantum-enhanced sensing down to the detection level of single photons and without postselection. When the switch is active, we observe a factor of improvement in precision of 1.27 for transmission measurement on a per-input-photon basis compared to the performance of a laser emitting an ideal coherent state and measured with the same detection efficiency as our setup. When the switch is inoperative, we observe no quantum advantage.

• Item Type: Articles
• Additional Information: This work was supported by Engineering and Physical Sciences Research Council (EPSRC), European Research Council (ERC), and UK Quantum Technology Hub in Quantum Enhanced Imaging (QuantIC). J. C. F. M. and J. G. R. acknowledge fellowship support from the Engineering and Physical Sciences Research Council. J. C. F. M. and J. G. R. acknowledge fellowship support from the Engineering and Physical Sciences Research Council under Grant Code No. EP/M024385/1.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Moreau, Dr Paul-Antoine
• Authors: Sabines-Chesterking, J., Whittaker, R., Joshi, S.K., Birchall, P.M., Moreau, P.-A., McMillan, A., Cable, H.V., O’Brien, J.L., Rarity, J.G., and Matthews, J.C.F.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review Applied
• Publisher: American Physical Society
• ISSN: 2331-7019
• ISSN (Online): 2331-7019
• Copyright Holders: Copyright © 2017 American Physical Society
• First Published: First published in Physical Review Applied 8(1):014016
• Publisher Policy: Reproduced under a Creative Commons License