DataSheet1_Alternative schemes for twin-field quantum key distribution with discrete-phase-randomized sources.pdf

The twin-field quantum key distribution (TF-QKD) protocol and its variants can overcome the well-known rate-loss bound without quantum repeaters, which have attracted significant attention. Generally, to ensure the security of these protocols, weak coherent states with continuous randomized phases are always assumed in the test mode. However, this assumption is difficult to meet in practice. To bridge the gap between theory and practice, we propose two alternative discrete-phase-randomized (DPR)-twin-field quantum key distribution protocols, which remove the phase sifting procedure in the code mode. Simulation results show that when compared with previous discrete-phase-randomized-twin-field quantum key distribution protocols, our modified protocols can significantly improve the secret key rate in the low channel loss range, which is very promising for practical twin-field quantum key distribution systems.

双场量子密钥分发（TF-QKD）协议及其变体能够在无需量子中继器的情况下克服已知的速率-损失界限，这一特性已引起广泛关注。通常，为确保这些协议的安全性，测试模式下均假设使用具有连续随机相位的弱相干态。然而，在实际操作中，这一假设难以实现。为弥合理论与实践之间的差距，我们提出了两种替代的离散相位随机化（DPR）-双场量子密钥分发协议，这些协议在码模式下去除了相位提取过程。仿真结果显示，与先前的离散相位随机化-双场量子密钥分发协议相比，我们的改进协议在低信道损耗范围内显著提高了密钥传输速率，这对于实际双场量子密钥分发系统而言极具前景。