Alkali-metal atomic magnetometers employing longitudinal carrier magnetic field have ultrahigh sensitivity to measure transverse magnetic fields and have been applied in a variety of precise-measurement science and te...Alkali-metal atomic magnetometers employing longitudinal carrier magnetic field have ultrahigh sensitivity to measure transverse magnetic fields and have been applied in a variety of precise-measurement science and technologies.In practice,the magnetometer response is not rigorously proportional to the measured transverse magnetic fields and the existing fundamental analytical model of this magnetometer is effective only when the amplitudes of the measured fields are very small.In this paper,we present a modified analytical model to characterize the practical performance of the magnetometer more definitely.We find out how the longitudinal magnetization of the alkali metal atoms vary with larger transverse fields.The linear-response capacity of the magnetometer is determined by these factors:the amplitude and frequency of the longitudinal carrier field,longitudinal and transverse spin relaxation time of the alkali spins and rotation frequency of the transverse fields.We give a detailed and rigorous theoretical derivation by using the perturbation-iteration method and simulation experiments are conducted to verify the validity and correctness of the proposed modified model.This model can be helpful for measuring larger fields more accurately and configuring a desirable magnetometer with proper linear range.展开更多
核磁共振陀螺(Nuclear Magnetic Resonance Gyroscope,NMRG)具有小体积、轻质化、低功耗等潜在优势,是当前惯性技术领域的热点研究方向之一。然而,目前其灵敏度与光学陀螺相比还有一定差距。为了分析核磁共振陀螺灵敏度(这里指角随机游...核磁共振陀螺(Nuclear Magnetic Resonance Gyroscope,NMRG)具有小体积、轻质化、低功耗等潜在优势,是当前惯性技术领域的热点研究方向之一。然而,目前其灵敏度与光学陀螺相比还有一定差距。为了分析核磁共振陀螺灵敏度(这里指角随机游走)的实际限制,基于Rb-Xe自旋交换光泵浦系统建立了相关模型。在此基础上,获得了NMRG灵敏度的影响因素,并推导了一个可以用来估计其实际灵敏度的公式。然后,分别以内腔体积8mm^(3)和1000mm^(3)的两个原子气室为例,研究了系统参数的影响,优化了NMRG的灵敏度。前者给出的理论灵敏度约为7.3×10^(-4)(°)/h^(1/2) ,而后者给出的理论灵敏度约为3.1×10^(-5)(°)/h^(1/2) ,表明NMRG具有很大的潜力。展开更多
Magnetic coils for specific requirements are widely used in modern quantum physics. In this study, a general analytical method of designing the shielded coils for generating an arbitrary axial magnetic field is propos...Magnetic coils for specific requirements are widely used in modern quantum physics. In this study, a general analytical method of designing the shielded coils for generating an arbitrary axial magnetic field is proposed. The theoretical formula for an axial magnetic field generated by a single shielded coil is obtained and used to construct specific coils. The structural parameters of these coils are determined by fitting the theoretical formula with their specific requirements. The feasibility of this method is proved by realizing four concrete kinds of coils: uniform magnetic field generating coils, gradient magnetic field generating coils, asymmetrical uniform magnetic field generating coils, and parabolic magnetic field generating coils. The correctness of these theoretical results is demonstrated by both the finite element simulations and the relevant experimental results. Furthermore, the application of this method is of great significance for developing the quantum physics and quantum devices in future.展开更多
基金the Hunan Graduate Research and Innovation Project(Grant No.CX2018B009)the Natural Science Foundation of Hunan(Grant No.2018JJ3608)+1 种基金the Research Project of National University of Defense Technology(Grant Nos.ZK170204 and ZZKY-YX-07-02)the National Natural Science Foundation of China(Grant Nos.61671458 and 61701515).
文摘Alkali-metal atomic magnetometers employing longitudinal carrier magnetic field have ultrahigh sensitivity to measure transverse magnetic fields and have been applied in a variety of precise-measurement science and technologies.In practice,the magnetometer response is not rigorously proportional to the measured transverse magnetic fields and the existing fundamental analytical model of this magnetometer is effective only when the amplitudes of the measured fields are very small.In this paper,we present a modified analytical model to characterize the practical performance of the magnetometer more definitely.We find out how the longitudinal magnetization of the alkali metal atoms vary with larger transverse fields.The linear-response capacity of the magnetometer is determined by these factors:the amplitude and frequency of the longitudinal carrier field,longitudinal and transverse spin relaxation time of the alkali spins and rotation frequency of the transverse fields.We give a detailed and rigorous theoretical derivation by using the perturbation-iteration method and simulation experiments are conducted to verify the validity and correctness of the proposed modified model.This model can be helpful for measuring larger fields more accurately and configuring a desirable magnetometer with proper linear range.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61701515 and 61671458)the Postdoctoral Science Foundation,China(Grant No.2017M613367)+1 种基金the Natural Science Foundation of Hunan Province,China(Grant No.2018JJ3608)the Research Project of National University of Defense Technology,China(Grant No.ZK170204)
文摘Magnetic coils for specific requirements are widely used in modern quantum physics. In this study, a general analytical method of designing the shielded coils for generating an arbitrary axial magnetic field is proposed. The theoretical formula for an axial magnetic field generated by a single shielded coil is obtained and used to construct specific coils. The structural parameters of these coils are determined by fitting the theoretical formula with their specific requirements. The feasibility of this method is proved by realizing four concrete kinds of coils: uniform magnetic field generating coils, gradient magnetic field generating coils, asymmetrical uniform magnetic field generating coils, and parabolic magnetic field generating coils. The correctness of these theoretical results is demonstrated by both the finite element simulations and the relevant experimental results. Furthermore, the application of this method is of great significance for developing the quantum physics and quantum devices in future.
