Single crystal diamond (<5 ppm nitrogen) containing native NV centers with coherence time of 150 μs was irradiated with 2 MeV alpha particles, with doses ranging from 1012 ion/cm2 to 1015 ion/cm2. The effect of ion damage on the coherence time of NV centers was studied using optically detected magnetic resonance and supplemented by fluorescence and Raman microscopy. A cross-sectional geometry was employed so that the NV coherence time could be measured as a function of increasing defect concentration along the ion track. Surprisingly, although the ODMR contrast was found to decrease with increasing ion induced vacancy concentration, the measured decoherence time remained undiminished at 150us despite the estimated vacancy concentration reaching a value of 40 ppm at the end of range. These results suggest that ion induced damage in the form of an increase in vacancy concentration does not necessarily result in a significant increase in the density of the background spin bath.

中文翻译：

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辐射损伤对金刚石中氮空位量子光学性质的影响

用 2 MeV α 粒子辐照含有天然 NV 中心、相干时间为 150 μs 的单晶金刚石（<5 ppm 氮），剂量范围为 1012 离子/平方厘米至 1015 离子/平方厘米。使用光学检测磁共振并辅以荧光和拉曼显微镜研究了离子损伤对 NV 中心相干时间的影响。采用横截面几何形状，以便可以测量 NV 相干时间作为沿离子轨道增加的缺陷浓度的函数。令人惊讶的是，尽管发现 ODMR 对比度随着离子诱导空位浓度的增加而降低，但尽管估计的空位浓度在范围结束时达到 40 ppm 的值，但测量的退相干时间在 150 微秒时仍然没有减少。