Measurement-device-independent quantum key distribution (MDI-QKD) removes all detector side channels and enables secure QKD with an untrusted relay. It is suitable for building a star-type quantum access network, where the complicated and expensive measurement devices are placed in the central untrusted relay and each user requires only a low-cost transmitter, such as an integrated photonic chip. Here, we experimentally demonstrate a 1.25 GHz silicon photonic chip-based MDI-QKD system using polarization encoding. The photonic chip transmitters integrate the necessary encoding components for a standard QKD source. We implement random modulations of polarization states and decoy intensities, and demonstrate a finite-key secret rate of 31 bps over 36 dB channel loss (or 180 km standard fiber). This key rate is higher than state-of-the-art MDI-QKD experiments. The results show that silicon photonic chip-based MDI-QKD, benefiting from miniaturization, low-cost manufacture and compatibility with CMOS microelectronics, is a promising solution for future quantum secure networks.

中文翻译：

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集成硅光子技术的高速测量设备无关的量子密钥分配

独立于测量设备的量子密钥分发（MDI-QKD）删除了所有检测器侧通道，并通过不受信任的中继器实现了安全的QKD。它适用于构建星型量子访问网络，该网络将复杂且昂贵的测量设备放置在中央不信任中继器中，并且每个用户仅需要一个低成本发射器，例如集成光子芯片。在这里，我们通过实验演示了使用极化编码的基于1.25 GHz硅光子芯片的MDI-QKD系统。光子芯片发射器集成了标准QKD源所需的编码组件。我们对偏振态和诱饵强度进行随机调制，并演示了在36 dB信道损耗（或180 km标准光纤）上31 bps的有限密钥秘密速率。该关键率高于最新的MDI-QKD实验。结果表明，基于硅光子芯片的MDI-QKD受益于小型化，低成本制造以及与CMOS微电子的兼容性，是未来量子安全网络的有希望的解决方案。