Solid-state magnetometers like the nitrogen-vacancy (NV) center in diamond have been of paramount importance for the development of quantum sensing with nanoscale spatial resolution. The underlying protocol is a Ramsey sequence, that imprints an external static magnetic field into the phase of the quantum sensor, which is subsequently read out. In this theoretical work we propose a sensing scheme that harnesses the hyperfine coupling between the NV center and a nearby nuclear spin to set a post-selection protocol. We show that concentrating valuable sensing information into a single successful measurement yields an improvement in sensitivity over Ramsey in the range of short transverse relaxation times. By considering realistic experimental conditions, we found that the detection of weak magnetic fields in the μT range can be achieved with a sensitivity of few tens of nTHz^−1/2 at cryogenic temperature (4K), and μTHz^−1/2 at room temperature.

固态磁力计，如金刚石中的氮空位 (NV) 中心，对于开发具有纳米级空间分辨率的量子传感至关重要。底层协议是一个拉姆齐序列，它将外部静磁场压印到量子传感器的相位中，随后被读出。在这项理论工作中，我们提出了一种传感方案，该方案利用 NV 中心和附近核自旋之间的超精细耦合来设置后选择协议。我们表明，将有价值的传感信息集中到一次成功的测量中，可以在较短的横向弛豫时间范围内提高 Ramsey 的灵敏度。通过考虑现实的实验条件，我们发现μ中弱磁场的检测T 范围可以在低温 (4K) 下以几十 nTHz ^-1/2的灵敏度实现，在室温下以μ THz ^-1/2的灵敏度实现。