Solid-state spin–photon interfaces that combine single-photon generation and long-lived spin coherence with scalable device integration—ideally under ambient conditions—hold great promise for the implementation of quantum networks and sensors. Despite rapid progress reported across several candidate systems, those possessing quantum coherent single spins at room temperature remain extremely rare. Here we report quantum coherent control under ambient conditions of a single-photon-emitting defect spin in a layered van der Waals material, namely, hexagonal boron nitride. We identify that the carbon-related defect has a spin-triplet electronic ground-state manifold. We demonstrate that the spin coherence is predominantly governed by coupling to only a few proximal nuclei and is prolonged by decoupling protocols. Our results serve to introduce a new platform to realize a room-temperature spin qubit coupled to a multiqubit quantum register or quantum sensor with nanoscale sample proximity.

固态自旋光子接口将单光子生成和长寿命自旋相干性与可扩展设备集成相结合（理想情况是在环境条件下），为量子网络和传感器的实现带来了巨大的希望。尽管几个候选系统取得了快速进展，但在室温下拥有量子相干单自旋的系统仍然极其罕见。在这里，我们报告了层状范德华材料（即六方氮化硼）中单光子发射缺陷自旋在环境条件下的量子相干控制。我们发现与碳相关的缺陷具有自旋三重态电子基态流形。我们证明自旋相干性主要由仅与几个近端原子核的耦合控制，并通过解耦协议延长。我们的研究结果旨在引入一个新平台，以实现室温自旋量子位与具有纳米级样本接近度的多量子位量子寄存器或量子传感器的耦合。