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用户提供了一种具有无条件安全性的安全密钥共享解决方案。然而，量子密钥分发仍受到设备不完善特性的严重威胁。特别是，在发送诱骗态时，经典脉冲相关性会危及系统安全性。为解决这一问题并简化实验需求，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。不同于传统诱骗态方案，我们提出一种新颖方法，可估算偶光子数分量所贡献相位误差率的理论上限。仿真结果表明，本协议在通信光纤中的传输距离可达305公里。此外，我们通过原理验证实验证明了该协议的可行性，在45 dB信道损耗下密钥率可达22.5 bps。本协议通过规避脉冲强度相关性安全漏洞，并采用6或8片随机相位替代连续随机相位，为构建量子网络提供了有前景的解决方案。