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arXiv · 1709.04618

Continuous-variable QKD over 50km commercial fiber

Yi-Chen Zhang·Zhengyu Li·Ziyang Chen·Christian Weedbrook·Yijia Zhao·Xiangyu Wang·Yundi Huang·Chunchao Xu·Xiaoxiong Zhang·Zhenya Wang·Mei Li·Xueying Zhang·Ziyong Zheng·Binjie Chu·Xinyu Gao·Nan Meng·Weiwen Cai·Zheng Wang·Gan Wang·Song Yu·Hong Guo
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Abstract

The continuous-variable version of quantum key distribution (QKD) offers the advantages (over discrete-variable systems) of higher secret key rates in metropolitan areas as well as the use of standard telecom components that can operate at room temperature. An important step in the real-world adoption of continuous-variable QKD is the deployment of field tests over commercial fibers. Here we report two different field tests of a continuous-variable QKD system through commercial fiber networks in Xi'an and Guangzhou over distances of 30.02 km (12.48 dB) and 49.85 km (11.62 dB), respectively. We achieve secure key rates two orders-of-magnitude higher than previous field test demonstrations. This is achieved by developing a fully automatic control system to create stable excess noise and by applying a rate-adaptive reconciliation protocol to achieve a high reconciliation efficiency with high success probability. Our results pave the way to achieving continuous-variable QKD in a metropolitan setting.

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Yi-Chen Zhang, Zhengyu Li, Ziyang Chen, Christian Weedbrook, Yijia Zhao, Xiangyu Wang, Yundi Huang, Chunchao Xu, Xiaoxiong Zhang, Zhenya Wang, Mei Li, Xueying Zhang, Ziyong Zheng, Binjie Chu, Xinyu Gao, Nan Meng, Weiwen Cai, Zheng Wang, Gan Wang, Song Yu, Hong Guo. 2019-05-30. Continuous-variable QKD over 50km commercial fiber. https://doi.org/10.1088/2058-9565%2Fab19d1

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