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arXiv · 2101.00276

Field Test of Twin-Field Quantum Key Distribution through Sending-or-Not-Sending over 428 km

Hui Liu·Cong Jiang·Hao-Tao Zhu·Mi Zou·Zong-Wen Yu·Xiao-Long Hu·Hai Xu·Shizhao Ma·Zhiyong Han·Jiu-Peng Chen·Yunqi Dai·Shi-Biao Tang·Weijun Zhang·Hao Li·Lixing You·Zhen Wang·Fei Zhou·Qiang Zhang·Xiang-Bin Wang·Teng-Yun Chen·Jian-Wei Pan
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Abstract

Quantum key distribution endows people with information-theoretical security in communications. Twin-field quantum key distribution (TF-QKD) has attracted considerable attention because of its outstanding key rates over long distances. Recently, several demonstrations of TF-QKD have been realized. Nevertheless, those experiments are implemented in the laboratory, remaining a critical question about whether the TF-QKD is feasible in real-world circumstances. Here, by adopting the sending-or-not-sending twin-field QKD (SNS-TF-QKD) with the method of actively odd parity pairing (AOPP), we demonstrate a field-test QKD over 428~km deployed commercial fiber and two users are physically separated by about 300~km in a straight line. To this end, we explicitly measure the relevant properties of the deployed fiber and develop a carefully designed system with high stability. The secure key rate we achieved breaks the absolute key rate limit of repeater-less QKD. The result provides a new distance record for the field test of both TF-QKD and all types of fiber-based QKD systems. Our work bridges the gap of QKD between laboratory demonstrations and practical applications, and paves the way for intercity QKD network with high-speed and measurement-device-independent security.

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Hui Liu, Cong Jiang, Hao-Tao Zhu, Mi Zou, Zong-Wen Yu, Xiao-Long Hu, Hai Xu, Shizhao Ma, Zhiyong Han, Jiu-Peng Chen, Yunqi Dai, Shi-Biao Tang, Weijun Zhang, Hao Li, Lixing You, Zhen Wang, Fei Zhou, Qiang Zhang, Xiang-Bin Wang, Teng-Yun Chen, Jian-Wei Pan. 2021-01-01. Field Test of Twin-Field Quantum Key Distribution through Sending-or-Not-Sending over 428 km. https://doi.org/10.1103/physrevlett.126.250502

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