Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

AIP Advances

Three techniques for measuring the transverse relaxation time of cesium atoms

Mengmeng Wei, Wenbin Yu, Min Zhou, Wei Huang, Yuanxing Liu, Xinye Xu

Published Mar 1, 2023• 4 citations
Publisher

Abstract

The transverse relaxation time (T2) is an important indicator to determine the fundamental sensitivity limit of alkali-metal atomic magnetometers. We propose a method based on the principle of longitudinal field modulation that obtains T2 by scanning the transverse static magnetic field. The previous technique of extracting T2 from the linewidth of the modulation frequency and the traditional magnetic-resonance-broadening-fitting method are also described. The T2 measurements of Cesium (Cs) atoms are carried out through these three methods, whose operating environments are applicable to different atomic magnetometers, respectively. The method that we propose can be used for obtaining the T2 of Cs atoms as well as detecting the transverse static magnetic field and is customized for the study of the Cs–Xenon ensemble for the construction of nuclear magnetic resonance gyroscopes. Moreover, the relationship between the limit sensitivities and cell temperatures is further studied in the experiment.

DOI
10.1063/5.0140593

Related papers

Comparison and analysis of methods for measuring the spin transverse relaxation time of rubidium atomic vapor

Lulu Zhang, Yongbiao Yang, Junye Zhao +2 more

The spin transverse relaxation time ( T 2 ) of atoms is an important indicator for magnetic field precision measurement. Especially in optically-pumped atomic magnetometer, the linewidth of the magnetic resonance signal is one of the most important parameters of sensitivity, which is inversely correlated with T 2 of atoms. In this paper, we propose four methods, namely spin noise spectroscopy signal fitting, radio-frequency free induction decay (RF-FID) signal fitting, ω m (modulation frequency)-broadening fitting, and magnetic resonance broadening fitting, for in-situ measurement T 2 of atomic vapor cells based on light-atom interactions. Meanwhile, T 2 of three Rubidium (Rb) atomic vapor cells with different parameters are measured and discussed by using these four methods. A comparative analysis visualizes the characteristics of the different methods and the effects of buffer gas on T 2 of Rb atoms. Through theoretical and experimental analysis, we assess the applicability of each method and concluded that the RF-FID signal fitting method provides the most accurate measurements due to the timing sequence control system, which results in a cleaner measurement environment. Furthermore, we demonstrate and qualitatively analyze the relationship between temperature and T 2 of Rb atoms. This work may offer valuable insights into the selection of atomic vapor cells and it is also applicable for the spin-exchange relaxation-free region.

arXiv:2312.06078•Optics Express•Nov 17, 2024•0 citations

Investigation on the methods to extend the transverse relaxation time of polarized alkali atoms

Yang-Ying Fu, Jie Yuan

In order to improve the sensitivity of radio-frequency atomic magnetometer, two methods to extend the transverse relaxation time of polarized alkali atoms are investigated. One way is the application of a non-relaxing coating, another way is the introduction of buffer gas into cell. A theory relaxation model is built, and the dependences of transverse relaxation time on buffer gas pressure, laser power, cell temperature, and magnetic-field gradient are obtained. The measurements of transverse relaxation time are carried out in a cesium atomic radio-frequency magnetometer. The optical experiment conditions which yield the highest sensitivity are determined in experiments. Experiments results indicate that the optimal pressure for neon is 200 Torr. The experimental results are in agreement with the theoretical ones. An ultimate sensitivity of 100 fT/Hz1/2 of the cesium atomic radio-frequency magnetometer has been achieved. This study helps further optimization of the cell performance and the sensitivity of radio-frequency atomic magnetometer.

National Conference on Laser Technology and Optoelectronics (LTO)•May 17, 2019•0 citations

Measuring Transverse Relaxation with a Single-Beam 894 nm VCSEL for Cs-Xe NMR Gyroscope Miniaturization

Qingyang Zhao, Ruochen Zhang, Hua Liu

The spin-exchange-pumped nuclear magnetic resonance gyroscope (NMRG) is a pivotal tool in quantum navigation. The transverse relaxation of atoms critically impacts the NMRG’s performance parameters and is essential for judging normal operation. Conventional methods for measuring transverse relaxation typically use dual beams, which involves complex optical path and frequency stabilization systems, thereby complicating miniaturization and integration. This paper proposes a method to construct a 133Cs parametric resonance magnetometer using a single-beam vertical-cavity surface-emitting laser (VCSEL) to measure the transverse relaxation of 129Xe and 131Xe. Based on this method, the volume of the gyroscope probe is significantly reduced to 50 cm3. Experimental results demonstrate that the constructed Cs-Xe NMRG can achieve a transverse relaxation time (T2) of 8.1 s under static conditions. Within the cell temperature range of 70 °C to 110 °C, T2 decreases with increasing temperature, while the signal amplitude inversely increases. The research lays the foundation for continuous measurement operations of miniaturized NMRGs.

Sensors•Sep 1, 2024•5 citations

Light narrowing of cesium magnetic-resonance lines in a radio-frequency atomic magnetometer

Y. Fu, Xiaohu Liu, Jie Yuan

The magnetic-resonance lines of alkali atoms are broadened considerably by the spin-exchange collisions for a radio-frequency magnetometer operating at high temperature. The resonance linewidths of cesium atoms are derived by solving the relaxation equations. When spin-exchange relaxation dominates, a light narrowing effect is predicted. For the cesium atomic radio-frequency magnetometer operates at high temperature, a remarkable narrowing of the cesium magnetic-resonance lines are observed by increasing the pump power. The Cs-Cs spin-exchange relaxation is partially suppressed by light narrowing. This study helps to expand the applications of radio-frequency magnetometers in the high-sensitivity radio-frequency magnetic-field detection.

AIP Advances•Jan 1, 2019•10 citations

The influence of longitudinal magnetic-field gradient on the transverse relaxation rate of cesium atoms

Y. Fu, Jiayue Yuan

Reducing the transverse relaxation rate of alkali atoms is crucial to improve the sensitivity of the magnetometers. In a perturbative treatment of the effects of the magnetic-field gradients, the transverse relaxation rates of alkali atoms are predicted to be proportional to the square of the longitudinal magnetic-field gradient. The theoretical predictions are confirmed in our experiments. The magnetic-field gradients in the vapor cell are measured by experiments. The magnetic-field gradient in the cell is suppressed drastically through compensating it with the compensation coils. Experimental results show that suppressing the magnetic-field gradient can reduce the transverse relaxation rate of alkali atoms significantly. This study contributes to the development of ultra-high sensitivity alkali atomic magnetometers.

AIP Advances•Nov 1, 2017•9 citations

Measurement of Relaxation Rates for NMOR Atomic Magnetometers Based on the Transient Dynamics

Zhenglong Lu, Jiali Liu, Xin Zhao +5 more

Abstract The relaxation rate is a fundamental parameter that characterizes the dynamics of atomic ensembles and plays a critical role in the performance of atomic magnetometers. In this study, a transient dynamics model for the NMOR magnetometer is developed based on multipole moment theory, revealing that the decay rate of the transient response to a step magnetic field from zero to certain value is determined by both transverse and longitudinal relaxation rates, whereas that to a step magnetic field from certain value to zero depends solely on the longitudinal relaxation rate. This distinction enables the independent determination of the two relaxation rates. To validate the proposed method, transverse and longitudinal relaxation rates are experimentally measured under various laser powers, which are consistent with the Lorentzian linewidths extracted from magnetic resonance curve fitting. This study provides valuable insights into atomic transient dynamics and contributes to the fast measurement of relaxation rates in NMOR magnetometers.

Advanced Quantum Technologies•Jan 1, 2026•0 citations
The transverse relaxation time (T2) is an important indicator to determine the fundamental sensitivity limit of alkali-metal atomic magnetometers. We propose a method based on the principle of longitudinal field modulation that obtains T2 by scanning the transverse static magnetic field. The previous technique of extracting T2 from the linewidth of the modulation frequency and the traditional magnetic-resonance-broadening-fitting method are also described. The T2 measurements of Cesium (Cs) atoms are carried out through these three methods, whose operating environments are applicable to different atomic magnetometers, respectively. The method that we propose can be used for obtaining the T2 of Cs atoms as well as detecting the transverse static magnetic field and is customized for the study of the Cs–Xenon ensemble for the construction of nuclear magnetic resonance gyroscopes. Moreover, the relationship between the limit sensitivities and cell temperatures is further studied in the experiment.
The spin transverse relaxation time ( T 2 ) of atoms is an important indicator for magnetic field precision measurement. Especially in optically-pumped atomic magnetometer, the linewidth of the magnetic resonance signal is one of the most important parameters of sensitivity, which is inversely correlated with T 2 of atoms. In this paper, we propose four methods, namely spin noise spectroscopy signal fitting, radio-frequency free induction decay (RF-FID) signal fitting, ω m (modulation frequency)-broadening fitting, and magnetic resonance broadening fitting, for in-situ measurement T 2 of atomic vapor cells based on light-atom interactions. Meanwhile, T 2 of three Rubidium (Rb) atomic vapor cells with different parameters are measured and discussed by using these four methods. A comparative analysis visualizes the characteristics of the different methods and the effects of buffer gas on T 2 of Rb atoms. Through theoretical and experimental analysis, we assess the applicability of each method and concluded that the RF-FID signal fitting method provides the most accurate measurements due to the timing sequence control system, which results in a cleaner measurement environment. Furthermore, we demonstrate and qualitatively analyze the relationship between temperature and T 2 of Rb atoms. This work may offer valuable insights into the selection of atomic vapor cells and it is also applicable for the spin-exchange relaxation-free region.
In order to improve the sensitivity of radio-frequency atomic magnetometer, two methods to extend the transverse relaxation time of polarized alkali atoms are investigated. One way is the application of a non-relaxing coating, another way is the introduction of buffer gas into cell. A theory relaxation model is built, and the dependences of transverse relaxation time on buffer gas pressure, laser power, cell temperature, and magnetic-field gradient are obtained. The measurements of transverse relaxation time are carried out in a cesium atomic radio-frequency magnetometer. The optical experiment conditions which yield the highest sensitivity are determined in experiments. Experiments results indicate that the optimal pressure for neon is 200 Torr. The experimental results are in agreement with the theoretical ones. An ultimate sensitivity of 100 fT/Hz1/2 of the cesium atomic radio-frequency magnetometer has been achieved. This study helps further optimization of the cell performance and the sensitivity of radio-frequency atomic magnetometer.
The spin-exchange-pumped nuclear magnetic resonance gyroscope (NMRG) is a pivotal tool in quantum navigation. The transverse relaxation of atoms critically impacts the NMRG’s performance parameters and is essential for judging normal operation. Conventional methods for measuring transverse relaxation typically use dual beams, which involves complex optical path and frequency stabilization systems, thereby complicating miniaturization and integration. This paper proposes a method to construct a 133Cs parametric resonance magnetometer using a single-beam vertical-cavity surface-emitting laser (VCSEL) to measure the transverse relaxation of 129Xe and 131Xe. Based on this method, the volume of the gyroscope probe is significantly reduced to 50 cm3. Experimental results demonstrate that the constructed Cs-Xe NMRG can achieve a transverse relaxation time (T2) of 8.1 s under static conditions. Within the cell temperature range of 70 °C to 110 °C, T2 decreases with increasing temperature, while the signal amplitude inversely increases. The research lays the foundation for continuous measurement operations of miniaturized NMRGs.
The magnetic-resonance lines of alkali atoms are broadened considerably by the spin-exchange collisions for a radio-frequency magnetometer operating at high temperature. The resonance linewidths of cesium atoms are derived by solving the relaxation equations. When spin-exchange relaxation dominates, a light narrowing effect is predicted. For the cesium atomic radio-frequency magnetometer operates at high temperature, a remarkable narrowing of the cesium magnetic-resonance lines are observed by increasing the pump power. The Cs-Cs spin-exchange relaxation is partially suppressed by light narrowing. This study helps to expand the applications of radio-frequency magnetometers in the high-sensitivity radio-frequency magnetic-field detection.
Reducing the transverse relaxation rate of alkali atoms is crucial to improve the sensitivity of the magnetometers. In a perturbative treatment of the effects of the magnetic-field gradients, the transverse relaxation rates of alkali atoms are predicted to be proportional to the square of the longitudinal magnetic-field gradient. The theoretical predictions are confirmed in our experiments. The magnetic-field gradients in the vapor cell are measured by experiments. The magnetic-field gradient in the cell is suppressed drastically through compensating it with the compensation coils. Experimental results show that suppressing the magnetic-field gradient can reduce the transverse relaxation rate of alkali atoms significantly. This study contributes to the development of ultra-high sensitivity alkali atomic magnetometers.
Abstract The relaxation rate is a fundamental parameter that characterizes the dynamics of atomic ensembles and plays a critical role in the performance of atomic magnetometers. In this study, a transient dynamics model for the NMOR magnetometer is developed based on multipole moment theory, revealing that the decay rate of the transient response to a step magnetic field from zero to certain value is determined by both transverse and longitudinal relaxation rates, whereas that to a step magnetic field from certain value to zero depends solely on the longitudinal relaxation rate. This distinction enables the independent determination of the two relaxation rates. To validate the proposed method, transverse and longitudinal relaxation rates are experimentally measured under various laser powers, which are consistent with the Lorentzian linewidths extracted from magnetic resonance curve fitting. This study provides valuable insights into atomic transient dynamics and contributes to the fast measurement of relaxation rates in NMOR magnetometers.