Research on the common mode suppression method of temperature noise in an NV color center spin magnetometer

Abstract

In this paper, two symmetrical magnetic formants in a nitrogen-vacancy (NV) ensemble are used to detect the two symmetrical spin states independently by means of microwave modulation and demodulation and frequency locking. Through the method of differential common mode cancellation, the spin information noise caused by temperature can be suppressed, and the measurement sensitivity of the NV magnetometer can be improved. In the experiment, a double formant magnetic detection system is built. By giving the same feedback to two symmetrical magnetic formants, we achieve differential common mode cancellation. From the experimental results, the temperature noise is reduced by 10 times, and the magnetic field sensitivity is increased from 126.8 pT Hz−1/2 to 13 pT Hz−1/2. The research realizes the suppression of temperature noise for the NV color center spin magnetometer, which provides technical support for improving the sensitivity and bandwidth of magnetometers.