High-rate quantum key distribution with compact state preparation and detection
- Guan-Jie Fan-Yuan
- Wei-Xin Xie
- De-Yong He
- Xiao-Juan Huang
- Shuang Wang
- Zhen-Qiang Yin
- Wei Chen
- Qiong Li
- Hao-Kun Mao
- Guo-Wei Zhang
- Yu-Long Wang
- Guang-Can Guo
- Zheng-Fu Han
2026-04-30
Quantum key distribution (QKD) is a promising technology for information-theoretic secure communications. The practicality of QKD systems is critical for large-scale network deployment, requiring both high key generation rate and miniaturized modules for quantum-state preparation and detection. Here, we report a deployable QKD system that achieves secure key rates of 60.33 ± 0.03 Mbps at 10 km and 3.08 ± 0.20 Mbps at 100 km. The system integrates a dual-parallel Mach–Zehnder encoder to achieve high-fidelity, unified preparation of polarization and decoy states via single-step modulation in a compact design. Meanwhile, we developed miniaturized single-photon avalanche detectors operating at 2.5 GHz, achieving high count rates while maintaining low noise. This high-performance and compact solution establishes a feasible roadmap for urban secure communication networks that require high capacity and bandwidth.