Decoy-State Quantum Key Distribution over 227 km with a Frequency-Converted Telecom Single-Photon Source
Year: 2026
Type: article
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 nondecoy schemes. This Letter broadens the scope of single-photon sources in future quantum networks by enabling long-distance quantum key distribution with realistic levels of single-photon purity.
Source: Physical Review Letters
DOI: 10.1103/5wwp-rbpm
Authors: Frederik Brooke Barnes, Roberto G. Pousa, Christopher L. Morrison, Zhe Xian Koong, Joseph Ho, Francesco Graffitti, John Jeffers, Daniel K. L. Oi, Brian D. Gerardot, Alessandro Fedrizzi
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,750
Funders: Fundación Cellex, Ministerio de Ciencia, Innovación y Universidades, Centres de Recerca de Catalunya, Royal Academy of Engineering, European Commission, Generalitat de Catalunya, FUNDACIÓ Privada MIR-PUIG, Engineering and Physical Sciences Research Council, Agencia Estatal de Investigación, NextGenerationEU
OpenAlex ID: W4417087239