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Japanese Journal of Applied Physics

Enhancing dual-band stabilization for twin-field quantum key distribution using laser frequency stabilization

Riho Amaki, Yohei Sugiyama, Yuto Shitaka, Isawa Yuta, Tomoki Tsuno, Daisuke Yoshida, Koji Nagano, Tomoyuki Horikiri, Daisuke Akamatsu, Feng-Lei Hong

Published May 23, 2025• 1 citation

Abstract

Abstract Twin-field quantum key distribution (TF-QKD) has attracted considerable attention in quantum communication for the extension of secure communication distance. In TF-QKD, precise photon phase control is required and has been realized using dual-band stabilization (DBS). In this study, we performed residual phase noise reduction in DBS using laser frequency stabilization. The achieved frequency stability of the light sources was better than 1 × 10 −12 when the averaging time is larger than 1 s, indicating that the laser frequency variation was less than 200 Hz at 1.5 μm. The integrated phase noise at 1 s was less than 200 mrad, and the corresponding quantum bit error rate at 1 s was less than 1% after applying laser frequency stabilization. This result demonstrates that the stringent phase stability requirements in TF-QKD can be achieved without relying on complex optical frequency combs, enabling a simpler and more cost-effective experimental setup.

DOI: 10.35848/1347-4065/addca8

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