Enhancing Long-distance Continuous-variable Quantum-key-distribution with an Error-correcting Relay

• URL: http://arxiv.org/abs/2512.11224v1
• Date: Fri, 12 Dec 2025 02:08:11 GMT
• Title: Enhancing Long-distance Continuous-variable Quantum-key-distribution with an Error-correcting Relay
• Authors: S. Nibedita Swain, Ryan J. Marshman, Josephine Dias, Alexander S. Solntsev, Timothy C. Ralph,
• Abstract summary: Noiseless linear amplifiers (NLAs) serve as an effective means to enable long-distance continuous-variable (CV) quantum key distribution (QKD)<n>We combine these two protocols to simultaneously compensate for thermal-loss effects and suppress phase noise, thereby enabling CV QKD that surpasses the repeaterless bound, the fundamental rate-distance limit, for repeaterless quantum communication systems.
• Score: 37.19059223604783
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Noiseless linear amplifiers (NLAs) serve as an effective means to enable long-distance continuous-variable (CV) quantum key distribution (QKD), even under realistic conditions with non-unit reconciliation efficiency. Separately, unitary averaging has been suggested to mitigate some stochastic noise, including phase noise in continuous-variable states. In this work, we combine these two protocols to simultaneously compensate for thermal-loss effects and suppress phase noise, thereby enabling long-distance CV QKD that surpasses the repeaterless bound, the fundamental rate-distance limit, for repeaterless quantum communication systems.

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