Quantum key distribution provides a promising solution for sharing secure keys between two distant parties with unconditional security. Nevertheless, quantum key distribution is still severely threatened by the imperfections of devices. In particular, the classical pulse correlation threatens security when sending decoy states. To address this problem and simplify experimental requirements, we propose a phase-matching quantum key distribution protocol without intensity modulation. Instead of using decoy states, we propose a novel method to estimate the theoretical upper bound on the phase error rate contributed by even-photon-number components. Simulation results show that the transmission distance of our protocol could reach 305 km in telecommunication fiber. Furthermore, we perform a proof-of-principle experiment to demonstrate the feasibility of our protocol, and the key rate reaches 22.5 bps under a 45 dB channel loss. Addressing the security loophole of pulse intensity correlation and replacing continuous random phase with 6 or 8 slices random phase, our protocol provides a promising solution for constructing quantum networks.

翻译：量子密钥分发为两个远距离方之间无条件安全地共享密钥提供了有前景的解决方案。然而，量子密钥分发仍受到器件不完善性的严重威胁。特别是，在发送诱骗态时，经典脉冲相关性威胁了安全性。为解决这一问题并简化实验要求，我们提出了一种无需强度调制的相位匹配量子密钥分发协议。不同于使用诱骗态，我们提出了一种新方法来估算由偶数光子数分量贡献的相位误差率理论上限。仿真结果表明，我们的协议在电信光纤中的传输距离可达305公里。此外，我们进行了原理验证实验以证明协议的可行性，在45 dB信道损耗下密钥速率达到22.5 bps。通过解决脉冲强度相关性的安全漏洞，并将连续随机相位替换为6或8个切片随机相位，我们的协议为构建量子网络提供了有前景的方案。