Nitrogen-vacancy (NV) centers in diamond have been developed into essential hardware units for a wide range of solid-state-based quantum technology applications. While such applications require the long spin lifetimes of the NV centers, they are often limited due to decoherence. In this study, we theoretically investigate the decoherence of NV-spin ensembles induced by nitrogen impurities (P1 centers), which are one of the most dominant and inevitable magnetic field noise sources in diamond. We combined cluster correlation expansion and density functional theory to compute the Hahn-echo spin-coherence time of the NV centers for a broad range of P1 concentrations. Results indicate a clear linear dependence of T₂ on P1 concentrations on a log scale with a slope of −1.06, which is in excellent agreement with previous experimental results. The interplay between the Jahn–Teller effect and the hyperfine interaction in the P1 center plays a critical role in determining the bath dynamics and the resulting NV decoherence. Our results provide a theoretical upper bound for the NV-spin T₂ over a wide range of P1 densities, serving as a key reference for materials optimization and spin bath characterization to develop highly coherent NV-based devices for quantum information technology.

金刚石中的氮空位 (NV) 中心已发展成为各种基于固态的量子技术应用的基本硬件单元。虽然此类应用需要 NV 中心的长自旋寿命，但它们通常由于退相干而受到限制。在这项研究中，我们从理论上研究了由氮杂质（P1 中心）引起的 NV 自旋系综的退相干，这是钻石中最主要和不可避免的磁场噪声源之一。我们结合聚类相关扩展和密度泛函理论来计算 NV 中心在广泛 P1 浓度范围内的 Hahn-echo 自旋相干时间。结果表明 T _{2具有明显的线性相关性}P1 浓度在对数尺度上，斜率为 -1.06，这与之前的实验结果非常一致。Jahn-Teller 效应和 P1 中心的超精细相互作用之间的相互作用在确定浴动力学和由此产生的 NV 退相干方面起着关键作用。_{我们的结果为宽范围 P1 密度上的 NV-spin T 2}提供了理论上限，作为材料优化和旋转浴表征的关键参考，以开发用于量子信息技术的高度相干的基于 NV 的器件。