Efficient measurement-device-independent quantum key distribution with heralded single-photon sources
Phys. Rev. Applied 25, 064024 – Published 5 June, 2026
DOI: https://doi.org/10.1103/7bm7-6fp2
Abstract
Measurement-device-independent quantum key distribution (MDI-QKD) can be immune to all detector-side loopholes. Compared with weak-coherent-state sources, heralded single-photon sources (HSPSs) can effectively suppress vacuum components, and thus substantially improve the transmission distance and secure key rate of MDI-QKD. Here, we experimentally demonstrate an efficient MDI-QKD protocol based on HSPSs without vacuum sources [Phys. Rev. A 98, 032303 (2018)]. It achieves a secure key rate that is more than 60 times higher than the previous reported work at 10-dB transmission loss and extends the maximum transmission loss to more than 30 dB. These improvements are attributed to the efficient protocol used and the high-quality HSPSs prepared in the experiment, which enable a Hong-Ou-Mandel interference visibility of 95.1% at 10 mW. Furthermore, with improvements to experimental technology, the maximum transmission distance is expected to exceed 400 km. Therefore, the current work is expected to play a crucial role in the future development of large-scale quantum communication networks.
