Practical free-space QKD enabled by SNSPDs
At IDQ, we are always thrilled to see new research enabled by the very best single-photon detection technology, i.e. superconducting nanowire single-photon detectors (SNSPs). Recently, two groups published ground-breaking results using free-space optical links for quantum communication using IDQ’s SNSPD Technology.
In a paper by M. Hassan et al. at the University of Tennessee, the authors report on a study into the effect of atmospheric turbulence on finite-size decoy-state BB84 quantum key distribution (QKD). They demonstrated the possibility of operating QKD in a turbulent and high loss (40 dB) environment with high efficiency and low noise SNSPDs. The paper also shows the huge improvement SNSPDs brought when compared to other detection technologies. QCE57702.2023.00133
Similarly, a collaboration led by M. Avesni et al. at the University of Padova has demonstrated a QKD system designed for full daylight operation at 1550nm. The team was able to remove a large portion of the noise coming from the sun’s background radiation, and they obtained a final QBER of 0.5% – quite impressive! https://doi.org/10.1038/s41534-021-00421-2
These results demonstrate that the impact on QKD caused by turbulence and daylight operation can be mitigated. They represent significant steps towards global-scale quantum networks using free-space and fibre links. They also highlight the critical role of SNSPDs in pushing scientific boundaries, and we’re proud to have contributed to their success. Congratulations to both teams on these achievements!
Learn more on IDQ’s Clavis XGR QKD system that can operate over >40 dB of loss with our new ID281 Pro SNSPD technology.
