2006/07/25 by P. A. Hiskett, D. Rosenberg, C. G. Peterson +5 · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1088/1367-2630/8/9/193
7 pages, 4 figures
arxiv created 2006/07/25 · arxiv updated 2009/12/01
Use of low-noise detectors can both increase the secret bit rate of long-distance quantum key distribution (QKD) and dramatically extend the length of a fibre optic link over which secure key can be distributed. Previous work has demonstrated use of ultra-low-noise transition-edge sensors (TESs) in a QKD system with transmission over 50 km. In this work, we demonstrate the potential of the TESs by successfully generating error-corrected, privacy-amplified key over 148.7 km of dark optical fibre at a mean photon number mu = 0.1, or 184.6 km of dark optical fibre at a mean photon number of 0.5. We have also exchanged secret key over 67.5 km that is secure against powerful photon-number-splitting attacks.