New Journal of Physics (Jan 2020)

Twin-field quantum key distribution with passive-decoy state

  • Jun Teng,
  • Feng-Yu Lu,
  • Zhen-Qiang Yin,
  • Guan-Jie Fan-Yuan,
  • Rong Wang,
  • Shuang Wang,
  • Wei Chen,
  • Wei Huang,
  • Bing-Jie Xu,
  • Guang-Can Guo,
  • Zheng-Fu Han

DOI
https://doi.org/10.1088/1367-2630/abbab7
Journal volume & issue
Vol. 22, no. 10
p. 103017

Abstract

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Twin-Field quantum key distribution (TF-QKD) and its variants, e.g. phase-maching QKD, sending-or-not-sending QKD, and no phase post-selection TFQKD promise high key rates at long distance to beat the rate distance limit without a repeater. The security proof of these protocols are based on decoy-state method, which is usually performed by actively modulating a variable optical attenuator together with a random number generator in practical experiments, however, active-decoy schemes like this may lead to side channel and could open a security loophole. To enhance the source security of TF-QKD, in this paper, we propose passive-decoy based TF-QKD, in which we combine TF-QKD with the passive-decoy method. And we present a simulation comparing the key generation rate with that in active-decoy, the result shows our scheme performs as good as active decoy TF-QKD, and our scheme could reach satisfactory secret key rates with just a few photon detectors. This shows our work is meaningful in practice.

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