Reference-frame-independent measurement-device-independent quantum key distribution (RFI-MDI-QKD) can remove all potential detector side-channel attacks and the requirement of real-time alignment of reference frames. However, all previous RFI-MDI-QKD implementations assume the perfect state preparation in sources, which is impractical and may lead to security loopholes. Here, we propose an RFI-MDI-QKD protocol which is robust against state preparation flaws. Comparing to the conventional six-state RFI-MDI-QKD, our scheme can be realized with only four flawed states, which improves the practical security of RFI-MDI-QKD and simplifies the experimental implementation. In addition, simulation results demonstrate that source flaws in Z basis have adverse effect on the performance of RFI-MDI-QKD while the source flaws in X and Y bases have almost no effect. We hope that this work could provide a valuable reference for practical implementations of RFI-MDI-QKD.

独立于参考帧的测量设备独立量子密钥分发 (RFI-MDI-QKD) 可以消除所有潜在的检测器侧信道攻击和实时对齐参考帧的要求。然而，之前所有的 RFI-MDI-QKD 实现都假设源中的状态准备是完美的，这是不切实际的，并且可能会导致安全漏洞。在这里，我们提出了一种 RFI-MDI-QKD 协议，该协议对状态准备缺陷具有鲁棒性。与传统的六态 RFI-MDI-QKD 相比，我们的方案只需四个缺陷态即可实现，这提高了 RFI-MDI-QKD 的实际安全性并简化了实验实现。此外，仿真结果表明Z中的源缺陷基对 RFI-MDI-QKD 的性能有不利影响，而X和Y基的源缺陷几乎没有影响。我们希望这项工作能为 RFI-MDI-QKD 的实际实现提供有价值的参考。