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 270 km in telecommunication fiber. Furthermore, we perform a proof-of-principle experiment to demonstrate the feasibility of our protocol, and the key rate reaches 14.1 bps under a 40 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以无条件安全性共享安全密钥提供了有前景的解决方案。然而，量子密钥分发仍严重受到设备不完美性的威胁。特别是在发送诱骗态时，经典脉冲相关性会威胁安全性。为解决此问题并简化实验要求，我们提出了一种无强度调制的相位匹配量子密钥分发协议。我们提出了一种新颖方法，无需使用诱骗态即可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，我们的协议在通信光纤中的传输距离可达270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40 dB信道损耗下，密钥率可达14.1 bps。通过解决脉冲强度相关性安全漏洞并将连续随机相位替换为6或8片离散随机相位，我们的协议为构建量子网络提供了有前景的解决方案。