English

2-GHz clock quantum key distribution over 260 km of standard telecom fiber

Quantum Physics 2012-03-21 v1

Abstract

We report a demonstration of quantum key distribution (QKD) over a standard telecom fiber exceeding 50 dB in loss and 250 km in length. The differential phase shift QKD protocol was chosen and implemented with 2 GHz system clock rate. By careful optimization of the 1-bit delayed Faraday-Michelson interferometer and the use of the super-conducting single photon detector (SSPD), we achieved a quantum bit error rate below 2% when the fiber length was no more than 205 km, and of 3.45% for the 260 km length fiber with 52.9 dB loss. We also improved the quantum efficiency of SSPD to obtain high key rate for 50 km length.

Keywords

Cite

@article{arxiv.1203.4323,
  title  = {2-GHz clock quantum key distribution over 260 km of standard telecom fiber},
  author = {Shuang Wang and Wei Chen and Jun-Fu Guo and Zhen-Qiang Yin and Hong-Wei Li and Zheng Zhou and Guang-Can Guo and Zheng-Fu Han},
  journal= {arXiv preprint arXiv:1203.4323},
  year   = {2012}
}