基于金刚石氮空位色心的矢量磁强计

Vector Magnetometer Based on Diamond Nitrogen Vacancy Color Center

金刚石氮空位(NV)色心作为高灵敏度的磁强计被广泛应用于各种领域。针对矢量磁场探测问题,在理论上建立了NV色心矢量磁场探测的物理模型,并通过仿真得到了磁场与NV色心晶向的定量关系;实验中,自主搭建了共聚焦光路测量系统,通过测量光探测磁共振(ODMR)及Rabi振荡光谱信号,得到了不同磁场角度下的信号,实验结果与理论仿真相符。磁场可检测带宽为0~10 kHz,更高的带宽可通过脉冲调控实现。磁场的角度分辨率为5°,当角度偏转5°,荧光光谱电子自旋共振(ESR)信号以及Rabi振荡信号发生明显变化,且通过噪声谱得到三轴磁场的最小可检测灵敏度为4.3nT√Hz。通过理论和实验验证了不同的矢量磁场会对NV色心产生不同的变化,表明其矢量磁强计的可行性。研究结果为以后NV色心磁强计的发展提供了技术支持。

As a high sensitive magnetometer, the color center of diamond nitrogen vacancy(NV) is widely used in various fields. For the problem of vector magnetic field detection, the physical model of NV color center vector magnetic field detection was established in theory, and the quantitative relationship between the magnetic field and NV color center crystal orientation was obtained through simulation. In the experiment, the confocal optical path measurement system was built independently, and the signals under the magnetic field with different angles were obtained by measuring the optical detection of magnetic resonance(ODMR) and Rabi oscillation spectral signals. The experimental results are consistent with the theoretical simulation. The detectable bandwidth of the magnetic field is 0-10 kHz, and higher bandwidth can be achieved by pulse regulation. The angle resolution of the magnetic field is 5°, and the electron spin resonance(ESR) signal and Rabi oscillation signal of the fluorescence spectrum change obviously when the angle deflects 5°, and the minimum detectable sensitivity of the triaxial magnetic field is 4.3nT√Hz by noise spectrum. It is verified by theory and experiment verification that different vector magnetic fields change differently to the NV color center, indicating the feasibility of the vector magnetometer. The research result provides technical support for the development of the NV color center magnetometer in the future.