2-GHz clock quantum key distribution over 260 km of standard telecom fiber
Eugen Leitl
eugen at leitl.org
Wed Mar 21 06:53:16 PDT 2012
http://arxiv.org/abs/1203.4323
2-GHz clock quantum key distribution over 260 km of standard telecom fiber
Shuang Wang, Wei Chen, Jun-Fu Guo, Zhen-Qiang Yin, Hong-Wei Li, Zheng Zhou,
Guang-Can Guo, Zheng-Fu Han
(Submitted on 20 Mar 2012)
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.
Subjects: Quantum Physics (quant-ph)
Journal reference: Optics Letters, 37, 1008-1010 (2012)
DOI: 10.1364/OL.37.001008
Cite as: arXiv:1203.4323v1 [quant-ph]
More information about the cypherpunks-legacy
mailing list