In state-of-the-art quantum key distribution (QKD) systems, the main limiting factor in increasing the key generation rate is the timing resolution in detecting photons. Here, we present and experimentally demonstrate a strategy to overcome this limitation, also for high-loss and long-distance implementations. We exploit the intrinsic wavelength correlations of entangled photons using wavelength multiplexing to generate a quantum secure key from polarization entanglement. The presented approach can be integrated into both fiber- and satellite-based quantum-communication schemes, without any changes to most types of entanglement sources. This technique features a huge scaling potential allowing to increase the secure key rate by several orders of magnitude as compared to non-multiplexed schemes.
@article{arxiv.2009.03691,
title = {Experimental wavelength-multiplexed entanglement-based quantum cryptography},
author = {Johannes Pseiner and Lukas Achatz and Lukas Bulla and Martin Bohmann and Rupert Ursin},
journal= {arXiv preprint arXiv:2009.03691},
year = {2021}
}