Polarization compensation for entanglement-based quantum key distribution
Sijie Yin, Tian-Wang Luo, Wenjuan Jiang, Xiyu Liu, Ya‐Fei Yu, Zhengjun Wei, Tianming Zhao, Junbin Fang, Jindong Wang · Optics Express · 2025
In quantum key distribution (QKD) systems using polarization entanglement, channel polarization perturbations significantly compromise both efficiency and security. To address the slow response and instability of current entanglement-based polarization compensation techniques for entanglement-based quantum key distribution, we propose a polarization compensation scheme based on an adaptive gradient descent algorithm. The system's performance is tested over a 10 km single-sided fiber channel. Results show that this scheme maintains long-term stability of the polarization state under both random and periodic perturbations. The average compensation time is 248 ms, with an entanglement source average visibility of 83.43% and an average quantum error rate of 8.28%. This method effectively mitigates polarization perturbation in entanglement-based quantum key distribution (QKD). These results are pivotal for the development of long-distance, multi-node quantum communication networks.