标题： 使用钻石中的氮空位中心进行电子自旋的局部纳米尺度探测 显示英文标题

标题： Local nanoscale probing of electron spins using NV centers in diamond

摘要： 替代氮原子在金刚石晶体（P1中心）中，一方面是一种用于创建氮空位（NV）中心的资源，这些NV中心已被广泛用作纳米尺度的量子传感器。 另一方面，P1的电子自旋是产生顺磁噪声的来源，通过缩短其相干时间而降低NV的性能。 因此，对氮浓度的精确量化对于优化基于金刚石的量子器件至关重要。 然而，基于光学吸收或电子顺磁共振的体材料表征方法常常忽略了氮含量的局部变化。 在这项工作中，我们使用氦离子显微镜在含有低浓度氮的金刚石晶体中预定位置制造纳米尺度的NV中心集合。 然后，我们利用这些基于NV的探针使用双电子-电子共振（DEER）技术，在230 ppb（每十亿原子中的原子数）的水平上测量局部的氮浓度。 此外，通过将DEER谱与数值模拟进行比较，我们成功确定了在离子注入过程中产生的其他未知顺磁缺陷的浓度，根据注入剂量的不同达到15 ppb。 显示英文摘要

摘要： Substitutional nitrogen atoms in a diamond crystal (P1 centers) are, on one hand, a resource for creation of nitrogen-vacancy (NV) centers, that have been widely employed as nanoscale quantum sensors. On the other hand, P1's electron spin is a source of paramagnetic noise that degrades the NV's performance by shortening its coherence time. Accurate quantification of nitrogen concentration is therefore essential for optimizing diamond-based quantum devices. However, bulk characterization methods based on optical absorption or electron paramagnetic resonance often overlook local variations in nitrogen content. In this work, we use a helium ion microscope to fabricate nanoscale NV center ensembles at predefined sites in a diamond crystal containing low concentrations of nitrogen. We then utilize these NV-based probes to measure the local nitrogen concentration on the level of 230 ppb (atomic parts per billion) using the double electron-electron resonance (DEER) technique. Moreover, by comparing the DEER spectra with numerical simulations, we managed to determine the concentration of other unknown paramagnetic defects created during the ion implantation, reaching 15 ppb depending on the implantation dose.