Decoy-state quantum key distribution over 227 km with a frequency-converted telecom single-photon source

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Barnes, Frederick and Pousa, Roberto G. and Morrison, Christopher L. and Koong, Zhe Xian and Ho, Joseph and Graffitti, Francesco and Jeffers, John and Oi, Daniel K. L. and Gerardot, Brian D. and Fedrizzi, Alessandro (2025) Decoy-state quantum key distribution over 227 km with a frequency-converted telecom single-photon source. Other. arXiv.org. (https://doi.org/10.48550/arXiv.2512.05101)

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Abstract

We implement a decoy-state quantum key distribution scheme using a telecom C-band single- emitter source. The decoy states are created by varying the optical excitation of the quantum emitter to modulate the photon number distribution. We provide an analysis of our scheme based on existing security proofs, allowing the calculation of secret key rates including finite key effects. This enables us to demonstrate, with a realistic single-photon source, positive secret key rates using our scheme over 227 km of optical fiber, equivalent to a loss tolerance one order of magnitude greater than non-decoy schemes. This work broadens the scope of single-photon sources in future quantum networks by enabling long-distance QKD with realistic levels of single-photon purity.

ORCID iDs

Barnes, Frederick, Pousa, Roberto G., Morrison, Christopher L., Koong, Zhe Xian, Ho, Joseph, Graffitti, Francesco, Jeffers, John ORCID logoORCID: https://orcid.org/0000-0002-8573-1675, Oi, Daniel K. L. ORCID logoORCID: https://orcid.org/0000-0003-0965-9509, Gerardot, Brian D. and Fedrizzi, Alessandro;
  • Item type:Monograph(Other)
    ID code:94947
    Dates:
    Date
    Event
    4 December 2025
    Published
    Subjects:Science > Physics
    Department:Faculty of Science > Physics
    Depositing user: Pure Administrator
    Date deposited:09 Dec 2025 16:21
    Last modified:05 Feb 2026 01:02
    URI:https://strathprints.strath.ac.uk/id/eprint/94947
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