Enhanced quantum sensing with a nitrogen-vacancy centre as gateway to the electron spin of phosphorus

以氮空位中心作为磷电子自旋通道的增强量子传感

• 批准号: 22K14560
• 负责人: ヘルブスレブ デイヴィト
• 金额: $ 2.91万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Early-Career Scientists
• 财政年份: 2022
• 资助国家: 日本
• 起止时间: 2022-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-22K14560/
• 关键词: NV centre; Dopant; Phosphorus; Quantum sensing; Nitrogen-vacancy centre; Defects

In order to investigate the key scientific question, "can the electron spins of phosphorus donors nearby NV centres in diamond be used as quantum sensors", at first a couple of phosphorus doped samples were measured. The doping concentrations were about 10^16 atoms/cm^3. However, as opposed to the initial measurements, there was no response from any defects/impurities nearby the measured NV centres. There are several potential explanations for this, which are researched currently. The first, a higher phosphorus concentration might be needed to have a fair chance to have a donor close enough to the NV centre. This will be tried by increasing the phosphorus concentration as much as possible. Secondly, the measurement method might be insufficient. To study this, we decided to look at a more "straightforward" (yet new) situation: coupling two NV centres. With the help of QST, we implanted molecules with multiple nitrogen atoms into phosphorus-doped diamond to have a high chance to have NV centres close together. The idea was to first try to use such couples for quantum sensing, as interaction with both NV centres is possible (if their orientation is different), hence it is easier compared to using dark spins. Although we were able to find couples of NV centers with different orientations fairly easily, they were either not stable (probably charge state), or their coherence times were very short (about a microsecond instead of close to a millisecond). Thirdly, we looked at a different measurement method that might be more suitable. The latter we will submit for publication soon.

为了研究关键的科学问题，“可以将钻石中NV中心附近的磷供体的电子旋转用作量子传感器”，首先，可以测量几个磷掺杂的样品。掺杂浓度约为10^16原子/cm^3。但是，与初始测量相反，在测量的NV中心附近没有任何缺陷/杂质的响应。目前有几种潜在的解释。首先，可能需要较高的磷浓度才能有足够的供体离足够接近NV中心的机会。这将通过尽可能增加磷浓度来尝试。其次，测量方法可能不足。为了研究这一点，我们决定研究一个更加“直接”（但新的）情况：耦合两个NV中心。在QST的帮助下，我们将具有多个氮原子的分子植入磷氧化的钻石中，有很大的机会使NV中心关闭。这个想法是首先尝试使用此类夫妻进行量子传感，因为与两个NV中心的相互作用是可能的（如果它们的方向不同），因此与使用暗旋转相比，它更容易。尽管我们能够很容易地找到具有不同方向的NV中心的夫妻，但它们要么不稳定（可能是充电状态），要么相干时间很短（大约是微秒而不是接近毫秒）。第三，我们研究了一种可能更合适的测量方法。后者我们将尽快提交出版。