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High-rate quantum key distribution exceeding 110 Mb s–1

Nature Photonics (2023)Cite this article

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Abstract

Quantum key distribution (QKD) can provide fundamentally proven secure communication. Towards application, the secret key rate (SKR) is a key figure of merit for any QKD system. The SKR has so far been limited to about a few megabits per second. Here we report a QKD system that is able to generate keys at a record high SKR of 115.8 Mb s–1 over a 10 km standard optical fibre, and distribute keys over up to 328 km of ultralow-loss fibre. Such abilities are attributed to a multipixel superconducting nanowire single-photon detector with an ultrahigh counting rate, an integrated transmitter that can stably encode polarization states with low error, a fast post-processing algorithm for generating keys in real time and the high system clock rate operation. The results demonstrate the feasibility of practical high-rate QKD with photonic techniques, thus opening its possibility for widespread applications.

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Fig. 1: Experimental set-up.
Fig. 2: Eight-pixel SNSPD characterization.
Fig. 3: SKRs at different fibre distances.
Fig. 4: System stability and post-processing capability.

Data availability

All of the data that support the findings of this study are reported in the main text and Supplementary Information. Source data are available from the corresponding authors on reasonable request.

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Acknowledgements

We would like to thank B. Bai, Y. Hong, X. Jiang, Z. Yuan, W.-J. Zhang and J. Zhang for helpful discussions and assistance. This work was supported by National Natural Science Foundation of China (grant no. 62031024, 62071151), Innovation Program for Quantum Science and Technology (grant no. 2021ZD0300300), Shanghai Municipal Science and Technology Major Project (grant no. 2019SHZDZX01), Shanghai Science and Technology Development Funds (grant no. 22JC1402900), Shanghai Academic/Technology Research Leader (grant no. 21XD1403800), Key-Area Research and Development Program of Guangdong Province (grant no. 2020B0303020001), Anhui Initiative in Quantum Information Technologies and Chinese Academy of Sciences. W.L. acknowledges support from the Natural Science Foundation of Shanghai (grant no. 22ZR1468100). F.X. acknowledges the support from the Tencent Foundation.

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Author notes

  1. These authors contributed equally: Wei Li, Likang Zhang.

Authors and Affiliations

  1. Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei, China

    Wei Li, Likang Zhang, Hao Tan, Yichen Lu, Sheng-Kai Liao, Qiang Zhang, Cheng-Zhi Peng, Feihu Xu & Jian-Wei Pan

  2. Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai, China

    Wei Li, Likang Zhang, Hao Tan, Yichen Lu, Sheng-Kai Liao, Qiang Zhang, Cheng-Zhi Peng, Feihu Xu & Jian-Wei Pan

  3. Hefei National Laboratory, University of Science and Technology of China, Hefei, China

    Sheng-Kai Liao, Qiang Zhang, Cheng-Zhi Peng, Feihu Xu & Jian-Wei Pan

  4. State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China

    Jia Huang, Hao Li, Zhen Wang & Lixing You

  5. School of Cyberspace Science, Faculty of Computing, Harbin Institute of Technology, Harbin, China

    Hao-Kun Mao, Bingze Yan & Qiong Li

  6. Jinan Institute of Quantum Technology, Jinan, China

    Yang Liu & Qiang Zhang

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Contributions

F.X. and J.-W.P. conceived the research and designed the experiments. W.L., L.Z. and F.X. performed the experiments. W.L., L.Z., H.T., Y.L. and F.X. analysed the data. W.L., S.-K.L., C.-Z.P. and F.X. developed the photonic chip. H.-K.M., B.Y. and Q.L. implemented the post-processing algorithms. J.H., H.L., Z.W. and L.Y. developed the SNSPDs, with input from Y.L. and Q.Z. W.L., F.X. and J.-W.P. wrote the manuscript, with input from all authors. All authors contributed materials and analysis tools.

Corresponding authors

Correspondence to Feihu Xu or Jian-Wei Pan.

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Li, W., Zhang, L., Tan, H. et al. High-rate quantum key distribution exceeding 110 Mb s–1. Nat. Photon. (2023). https://doi.org/10.1038/s41566-023-01166-4

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