Park, Chang Hoon Woo, Min Ki Park, Byung Kwon Kim, Yong-Su Baek, Hyeon jun Lee, Seung-Woo Lim, Hyang-Tag Jeon, Seung-Woo Jung, Hojoong Kim, Sangin Han, Sang-Wook 2024-01-19T12:02:50Z 2024-01-19T12:02:50Z 2022-05-12 2022-05 2056-6387 https://pubs.kist.re.kr/handle/201004/115228 Developing quantum key distribution (QKD) has been recently directed toward distance extension and network expansion for real-world secure communications. Considering a recent report on a quantum communication network over 4,600 km, it seems that QKD networks using conventional protocols have been sufficiently studied. However, although the twin-field QKD (TF-QKD) proposed for long-distance QKD has been studied deeply enough to succeed the demonstrations over 428- and 511-km deployed fibers, TF-QKD networks have been verified only for a ring network. In this work, we propose a star topological 2 x N TF-QKD network scheme, where the coherence maintenance issue, being the primary obstacle to implementing TF-QKD, can be minimized by the automatic mode-matching feature of the Sagnac-based plug-and-play architecture. A lower number of active controllers is required for our scheme in comparison with one-way TF-QKD networks. Moreover, our scheme adopts a cost-effective configuration that requires only a single pair of single-photon detectors for the entire network system. We conducted a proof-of-concept experiment over a 50-km fiber successfully, achieving an average secret key rate of 1.31 x 10(-4 )bit per pulse (1.52 bit per second) with the finite-size effect. English The University of New South Wales (UNSW Australia) | Nature Publishing Group 2xN twin-field quantum key distribution network configuration based on polarization, wavelength, and time division multiplexing Article 10.1038/s41534-022-00558-8 1 npj Quantum Information, v.8, no.1 npj Quantum Information 8 1 Y scie scopus 000789840700001 Quantum Science & Technology Physics, Applied Physics, Atomic, Molecular & Chemical Physics, Condensed Matter Physics Article