核磁共振陀螺中EPR信号响应不对称性研究  

Asymmetry of EPR signal response in nuclear magnetic resonance gyroscope

作　　者：鱼在洋 郑锦韬 张洋 汪之国[2,3] 孙辉 熊志强 罗晖[2,3] Yu Zai-Yang;Zheng Jin-Tao;Zhang Yang;Wang Zhi-Guo;Sun Hui;Xiong Zhi-Qiang;Luo Hui(School of Physics and Information Technology,Shaanxi Normal University,Xi’an 710049,China;College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,China;Interdisciplinary Center of Quantum Information,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]陕西师范大学,物理学与信息技术学院,西安710049 [2]国防科技大学前沿交叉学科学院,长沙410073 [3]国防科技大学量子信息学科交叉中心,长沙410073

出　　处：《物理学报》2022年第22期58-65,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12174446,61671458)资助的课题。

摘　　要：核磁共振陀螺具有高精度、小体积、低功耗等优点,是目前陀螺仪研究领域的热点之一.陀螺中的碱金属原子自旋弛豫时间通常在10^(-5)s量级,远小于在通常原子磁力仪中的弛豫时间.研究了短弛豫时间原子自旋对不同方向的振荡磁场EPR响应的差异,分析了基于EPR信号测量中心频率方法的偏差与弛豫时间的关系,并从理论上给出了修正.提出了一种基于XY轴信号相位差测量横向弛豫时间的方法,可以实现对弛豫时间的准确快速测量.在实验上以^(87)Rb原子为例比较了几种测量方式的准确性和适用性,其中半高宽拟合法受到系统延迟时间的影响较大并有其测量极限,相位测量法受到探测光角度影响较大,但测量范围更广,且抗干扰能力更强.研究对于准确测量核磁共振陀螺参数,提高陀螺性能的研究具有重要意义.The spin relaxation time of alkali atoms in nuclear magnetic resonance gyroscope is usually on the order of 10^(-5)s, which is much less than that in atomic magnetometers. The response of electron paramagnetic resonance signals of atoms with short relaxation time is asymmetric in different directions under oscillating magnetic fields, which makes the measurement results of atomic transverse relaxation time and Larmor frequency different. In this work this phenomenon is analyzed based on Bloch equation theory and the theoretical correction is given. The shorter the relaxation time, the greater the differences of the response intensity and resonance frequency of the electron paramagnetic resonance signal under different magnetic field directions will be. Using this property, the transmission delay time of the system can be measured accurately. In this paper proposed is a method of measuring transverse relaxation time based on the difference between signal phases in X-axis direction and Y-axis direction, which can accurately and quickly measure very short transverse relaxation time. The difference between the half-width fitting method and the phase measurement method is compared by measuring the transverse relaxation times of ^(87)Rb atoms under different magnetic field intensities.The half-width fitting method is greatly affected by the transmission delay time and has its measurement limit.The phase measurement method is greatly affected by the angle of the probe light, but the measurement range is wider and the anti-magnetic interference ability is stronger.

关 键 词：原子磁力仪 布洛赫方程 幅频响应 横向弛豫时间 

分 类 号：O482.532[理学—固体物理] TN96[理学—物理]