Abstract Surface functionalization of diamonds is an important topic for the negatively charged nitrogen-vacancy (NV−) center based quantum sensors. We investigate the electronic properties of oxidized diamond (111) surfaces and their effects on the NV− centers using the density of functional theory. The results show that the epoxy oxidized diamond (111) surface has neither surface spin noises nor inter-bandgap states and also has a positive electron affinity (1.85 eV) with nearly 99% preferential alignment of nitrogen-vacancy, indicating the epoxy oxidized (111) surface could be a perfect host of the NV− centers. Additionally, we make further examinations by placing an NV− center ∼1 nm from the epoxy oxidized (111) surface. The results indicate that the epoxy oxidized (111) surface has no obvious effects on the defect levels and optical transitions of the single NV− center. To the best our knowledge, the epoxy oxidized (111)-(2 × 1) surface may be the first diamond surface that not only theoretically satisfies the electronic requirements of shallow NV− centers but can also be fabricated through the oxidization process. Therefore, the epoxy oxidized diamond (111)-(2 × 1) surface is the most promising candidate to be applied in NV-based quantum sensors.

中文翻译：

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用于基于氮空位的量子传感器的环氧氧化金刚石 (111)-(2 × 1) 表面

摘要 金刚石的表面功能化是基于负电荷氮空位 (NV-) 中心的量子传感器的一个重要课题。我们使用泛函密度理论研究了氧化金刚石 (111) 表面的电子特性及其对 NV− 中心的影响。结果表明，环氧氧化金刚石 (111) 表面既没有表面自旋噪声也没有带隙状态，并且还具有正电子亲和力 (1.85 eV)，氮空位优先排列接近 99%，表明环氧氧化 (111) ) 表面可能是 NV− 中心的完美宿主。此外，我们通过在距环氧树脂氧化的 (111) 表面约 1 nm 处放置一个 NV− 中心来进行进一步检查。结果表明，环氧树脂氧化的 (111) 表面对单个 NV− 中心的缺陷水平和光学跃迁没有明显影响。据我们所知，环氧树脂氧化的 (111)-(2 × 1) 表面可能是第一个不仅理论上满足浅 NV− 中心电子要求而且还可以通过氧化工艺制造的金刚石表面。因此，环氧氧化金刚石（111）-（2×1）表面是最有希望应用于基于NV的量子传感器的候选者。