We experimentally demonstrated a sub-Mbps key rate Gaussian-modulated coherent-state continuous-variable quantum key distribution (CV-QKD) over 100 km transmission distance. To efficiently control the excess noise, the quantum signal and the pilot tone are co-transmitted in fiber channel based on wide-band frequency and polarization multiplexing methods. Furthermore, a high-accuracy data-assisted time domain equalization algorithm is carefully designed to compensate the phase noise and polarization variation in low signal-to-noise ratio. The asymptotic secure key rate (SKR) of the demonstrated CV-QKD is experimentally evaluated to be 10.36 Mbps, 2.59 Mbps, and 0.69 Mbps over transmission distance of 50 km, 75 km, and 100 km, respectively. The experimental demonstrated CV-QKD system significantly improves transmission distance and SKR compared to the state-of-art GMCS CV-QKD experimental results, and shows the potential for long-distance and high-speed secure quantum key distribution.
@article{arxiv.2212.11534,
title = {Sub-Mbps key-rate continuous-variable quantum key distribution with local-local-oscillator over 100 km fiber},
author = {Yaodi Pi and Heng Wang and Yan Pan and Yun Shao and Yang Li and Jie Yang and Yichen Zhang and Wei Huang and Bingjie Xu},
journal= {arXiv preprint arXiv:2212.11534},
year = {2023}
}