Wang Zhecheng, Kong Fei, Zhao Pengju, Huang Zhehua, Yu Pei, Wang Ya, Shi Fazhan, Du Jiangfeng
CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China.
CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
Sci Adv. 2022 Aug 12;8(32):eabq8158. doi: 10.1126/sciadv.abq8158. Epub 2022 Aug 10.
Developing robust microwave-field sensors is both fundamentally and practically important with a wide range of applications from astronomy to communication engineering. The nitrogen vacancy (NV) center in diamond is an attractive candidate for such purpose because of its magnetometric sensitivity, stability, and compatibility with ambient conditions. However, the existing NV center-based magnetometers have limited sensitivity in the microwave band. Here, we present a continuous heterodyne detection scheme that can enhance the sensor's response to weak microwaves, even in the absence of spin controls. Experimentally, we achieve a sensitivity of 8.9 pT Hz for microwaves of 2.9 GHz by simultaneously using an ensemble of ~ 2.8 × 10 NV centers within a sensor volume of 4 × 10 mm. Besides, we also achieve 1/ scaling of frequency resolution up to measurement time of 10,000 s. Our scheme removes control pulses and thus will greatly benefit practical applications of diamond-based microwave sensors.
开发强大的微波场传感器在从天文到通信工程等广泛应用中，无论从基础层面还是实际层面都具有重要意义。金刚石中的氮空位（NV）中心因其磁敏性、稳定性以及与环境条件的兼容性，是实现这一目的的极具吸引力的候选对象。然而，现有的基于NV中心的磁力计在微波频段的灵敏度有限。在此，我们提出一种连续外差检测方案，即使在没有自旋控制的情况下，该方案也能增强传感器对微弱微波的响应。通过实验，我们在4×10立方毫米的传感器体积内同时使用约2.8×10个NV中心的集合，实现了对2.9吉赫兹微波8.9皮特斯拉每赫兹的灵敏度。此外，我们还在长达10000秒的测量时间内实现了频率分辨率的1/缩放。我们的方案去除了控制脉冲，因此将极大地有利于基于金刚石的微波传感器的实际应用。
