Research On Single-channel Three-axis Vector Magnetic Sensing Method Of Diamond Nitrogen Vacancy Spin Structure

In recent years,the diamond nitrogen vacancy spin structure has become a research hotspot in the field of quantum sensing due to its small size,high sensitivity,long coherence time and excellent characteristics of working at room temperature.Among them,the weak magnetic detection technology based on the diamond nitrogen vacancy spin structure has also made significant progress.Based on the research of this subject,this paper studies the vector magnetic sensing model of the diamond nitrogen vacancy spin structure?And proposes a single-channel vector magnetic field information detection method based on the diamond nitrogen vacancy spin structure.In order to reduce the external environmental noise and the influence of geomagnetism on the detection accuracy of current magnetic sensors,this paper also designs an automatic magnetic compensation system for the compensation of interference magnetic fields and geomagnetism in the experimental detection environment.First of all,this paper introduces the mechanism of single-channel triaxial vector magnetic sensing of diamond nitrogen vacancy spin structure.Starting from the properties of diamond and nitrogen vacancy spin structure,the magnetic sensing mechanism of diamond nitrogen vacancy spin structure is theoretically deduced in detail,and a vector detection model of nitrogen vacancy spin structure is proposed.Based on the vector detection model of nitrogen vacancy spin structure,a single-channel triaxial vector magnetic sensing method of nitrogen vacancy spin structure is proposed,and the principle of single-channel triaxial vector magnetic sensing of nitrogen vacancy spin structure is introduced in detail.Then,this paper designs a single-channel three-axis vector magnetic sensing detection system based on the principle of nitrogen vacancy spin structure three-axis vector magnetic sensing.Mainly carried out the design of microwave source module,optical path integration system,data acquisition system and automatic magnetic compensation system.The design method and function of each module were elaborated.Finally,the construction of a singlechannel three-axis vector magnetic sensing platform was completed,and the system's remanence test and magnetic noise compensation test were carried out.The results of the residual magnetization compensation test show that the automatic compensation device designed in this paper can realize a stable magnetic field environment in the range of ?1.7n T in the magnetic shielding cylinder.Finally,the magnetic sensing test and characterization are carried out for the singlechannel three-axis vector magnetic sensing method of the nitrogen vacancy spin structure designed in this paper.First,the four pairs of magnetic resonance peaks of the nitrogen vacancy spin structure are tested.The incidence angle of the external bias magnetic field that can achieve the same frequency difference of the four pairs of magnetic resonance peaks is theoretically calculated,and the initial values of the four pairs of magnetic resonance peaks are tested.Then,four pairs of magnetic resonance peaks are proposed to calculate the three-axis magnetic field information,and the three-axis magnetic field information is measured and analyzed.The experimental test results show that the single-channel three-axis vector magnetic sensing method designed in this paper can realize the measurement of the three-axis vector magnetic field information.Through the theoretical calculation,it is known that there is an angular error between the triaxial vector magnetic field and the actual magnetic field detected by the nitrogen vacancy spin structure single-channel three-axis vector magnetic sensing method,and the error angles are 1.3° and 8.2°,respectively.Compared with the conventional three-axis magnetic information detection method,the single-channel three-axis magnetic information detection method proposed in this paper has a simpler detection process and saves experimental cost and experimental space.