2011/06/30 by Lars Lydersen, Mohsen K. Akhlaghi, A. Hamed Majedi +2 · 2 citations
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1088/1367-2630/13/11/113042
published as New J. Phys. 13, 113042 (2011) · Expanded discussions, updated references. 9 pages, 8 figures
arxiv created 2011/11/16 · arxiv updated 2015/03/19
We experimentally demonstrate that a superconducting nanowire single-photon detector is deterministically controllable by bright illumination. We found that bright light can temporarily make a large fraction of the nanowire length normally-conductive, can extend deadtime after a normal photon detection, and can cause a hotspot formation during the deadtime with a highly nonlinear sensitivity. In result, although based on different physics, the superconducting detector turns out to be controllable by virtually the same techniques as avalanche photodiode detectors. As demonstrated earlier, when such detectors are used in a quantum key distribution system, this allows an eavesdropper to launch a detector control attack to capture the full secret key without being revealed by to many errors in the key.