A cost-efficient quantum access network with qubit-based synchronization

• DOI: 10.48550/arxiv.2308.14385
• Publication Date: 2023-01-01
• Authors: Chunfeng Huang; Ye Chen; Tingting Luo; Wenjie He; Xin Liu; Zhenrong Zhang; Kejin Wei
• Keywords: Quantum key distribution

Quantum Key Distribution (QKD) is a physical layer encryption technique that enables two distant parties to exchange secure keys with information-theoretic security. In the last decades, QKD has transitioned from laboratory research real-world applications, including multi-user quantum access networks (QANs). This network structure allows users share single-photon detector at node through time-division multiplexing, thereby significantly reducing cost. However, current QAN implementations require additional hardware for auxiliary tasks such as time synchronization. To address this issue, we propose cost-efficient uses qubit-based approach, transmitted qubits facilitate synchronization, eliminating need synchronization hardware. We tested our scheme by implementing and successfully achieved average key rates of $53.84$ kbps $71.90$ each user over 50-km commercial fiber spool. addition, investigated capacity under cross-talk loss conditions. The simulation results demonstrate can support 64 up 1070~bps. Our work provides feasible cost-effective way implement network, further promoting widespread application QKD.