The studies of many-body dynamics of interacting spin ensembles, as well as quantum sensing in solid state systems, are often limited by the need for high spin concentrations, along with efficient decoupling of the spin ensemble from its environment. In particular, for an ensemble of nitrogen-vacancy (NV) centers in diamond, high conversion efficiencies between nitrogen (P1) defects and NV centers are essential while maintaining long coherence times of an NV ensemble. In this work, we study the effect of electron irradiation on the conversion efficiency and the coherence time of various types of diamond samples with different initial nitrogen concentrations. The samples were irradiated using a 200 keV transmission electron microscope. Our study reveals that the efficiency of NV creation strongly depends on the initial conversion efficiency and on the initial nitrogen concentration. The irradiation of the examined samples exhibits an order of magnitude improvement in the NV concentration (up to ∼1011 NV/cm...

中文翻译：

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通过 TEM 辐照提高金刚石中氮空位中心的浓度

相互作用的自旋系综的多体动力学研究，以及固态系统中的量子传感，通常受到对高自旋浓度以及自旋系综与其环境有效解耦的需要的限制。特别是，对于金刚石中氮空位 (NV) 中心的集合，氮 (P1) 缺陷和 NV 中心之间的高转换效率是必不可少的，同时保持 NV 集合的长相干时间。在这项工作中，我们研究了电子辐照对不同初始氮浓度的各类金刚石样品的转换效率和相干时间的影响。使用 200 keV 透射电子显微镜对样品进行辐照。我们的研究表明，NV 产生的效率很大程度上取决于初始转化效率和初始氮浓度。受检样品的辐照表现出 NV 浓度的数量级提高（高达 ~1011 NV/cm ...