The ability to communicate quantum information over long distances is of central importance in quantum science and engineering¹. Although some applications of quantum communication such as secure quantum key distribution^2,3 are already being successfully deployed^4,5,6,7, their range is currently limited by photon losses and cannot be extended using straightforward measure-and-repeat strategies without compromising unconditional security⁸. Alternatively, quantum repeaters⁹, which utilize intermediate quantum memory nodes and error correction techniques, can extend the range of quantum channels. However, their implementation remains an outstanding challenge^{10,11,12,13,14,15,16}, requiring a combination of efficient and high-fidelity quantum memories, gate operations, and measurements. Here we use a single solid-state spin memory integrated in a nanophotonic diamond resonator^17,18,19 to implement asynchronous photonic Bell-state measurements, which are a key component of quantum repeaters. In a proof-of-principle experiment, we demonstrate high-fidelity operation that effectively enables quantum communication at a rate that surpasses the ideal loss-equivalent direct-transmission method while operating at megahertz clock speeds. These results represent a crucial step towards practical quantum repeaters and large-scale quantum networks^20,21.

长距离传输量子信息的能力在量子科学和工程中至关重要¹。尽管量子通信的一些应用，如安全量子密钥分发^2,3已经成功部署^4,5,6,7，但它们的范围目前受到光子损失的限制，并且无法使用直接的测量和重复策略进行扩展而不妥协无条件安全⁸．或者，利用中间量子存储器节点和纠错技术的量子中继器^{9可以扩展量子通道的范围。}然而，它们的实施仍然是一个突出的挑战^{10,11,12,13,14,15,16}，需要结合高效和高保真量子存储器、门操作和测量。^{在这里，我们使用集成在纳米光子金刚石谐振器17、18、19}中的单个固态自旋存储器来实现异步光子贝尔态测量，这是量子中继器的关键组件。在原理验证实验中，我们展示了高保真操作，该操作有效地实现了量子通信，其速率超过了理想的损耗等效直接传输方法，同时以兆赫时钟速度运行。这些结果代表了迈向实用量子中继器和大规模量子网络的关键一步^20,21。