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

IEEE/CAA Journal of Automatica Sinica

Atomic Spin Polarization Controllability Analysis: A Novel Controllability Determination Method for Spin-Exchange Relaxation-Free Co-Magnetometers

Zhuo Wang, Sixun Liu, Ruigang Wang, Linlin Yuan, Jiong Huang, Yueyang Zhai, Sheng Zou

Published Dec 10, 2021• 33 citations
Publisher

Abstract

This paper investigates the atomic spin polarization controllability of spin-exchange relaxation-free co-magnetometers (SERFCMs). This is the first work in the field of controllability analysis for the atomic spin ensembles systems, whose dynamic behaviors of spin polarization are described by the Bloch equations. Based on the Bloch equations, a state-space model of the atomic spin polarization for SERFCM is first established, which belongs to a particular class of nonlinear systems. For this class of nonlinear systems, a novel determination method for the global state controllability is proposed and proved. Then, this method is implemented in the process of controllability analysis on the atomic spin polarization of an actual SERFCM. Moreover, a theoretically feasible and reasonable solution of the control input is proposed under some physical constraints, with whose limitation of realistic conditions, the controller design can be accomplished more practically and more exactly. Finally, the simulation results demonstrate the feasibility and validation of the proposed controllability determination method.

DOI
10.1109/jas.2021.1004383

Related papers

Reachability Analysis of The Atomic Spin Polarization for Spin-Exchange Relaxation-Free Atomic Magnetometers

Ruigang Wang, Zhuo Wang, Chong Ma +4 more

This paper is the first work to innovatively analyze and determine the reachability of atomic spin polarization of Spin-Exchange Relaxation-Free Atomic Magnetometers (SERFAMs), whose dynamic behaviors described by the Bloch equations. Then, it is transformed into a cybernetic model to analyze the reachability. The results show that the degree of freedom of state transition of atomic spin polarization is not consistent with the input dimension. Although this is contrary to the physical intuition, it corresponds to the point of cybernetics. The simulation results verify this conclusion. This work is an interesting case of applying cybernetics to the study of physics, which broadens the way of thinking for the performance analysis of atomic spin polarization system.

International Conference on Control and Robotics (ICCR)•Dec 2, 2022•1 citation

A Data-driven Physical Mechanism Modeling Method for the Spin-Exchange Relaxation-Free Comagnetometer

Feng Li, Zhuo Wang, Min Zhang +3 more

The Spin-Exchange Relaxation-Free Comagnetometer (SERFCM) is a new quantum instrument with ultra-high accuracy. Normally, the atomic ensembles of SERFCM operate in an open-loop state, which is not conducive to long-term high-precision measurements. In order to realize closed-loop control of its atomic polarization state, it is necessary to model and analyze the dynamic characteristics of the SERFCM system. In this paper, a Data-driven physical mechanism (DDPM) modeling method is proposed to realize the modeling of the SERFCM, a multi-input multi-output system. First, the state space equations of the SERFCM are established based on the Bloch equation, which are transformed into a discrete transfer function matrix. Then, based on the criterion of least variance in estimation, we realize the modeling of the discrete transfer function matrix using the excitation input data, the measured output data, and the estimated output data. Finally, the simulation results of modeling under different longitudinal magnetic fields confirm the validity of the proposed method. This work enables the online modeling of SERFCM system and facilitates the analysis of the effects of various parameters on the dynamic characteristics.

IEEE Data Driven Control and Learning Systems Conference (DDCLS)•May 12, 2023•0 citations

Determination of Spin Polarization in Spin-Exchange Relaxation-Free Atomic Magnetometer Using Transient Response

Junpeng Zhao, Ming Ding, Jixi Lu +5 more

A novel method to determine the spin polarization and its distribution for a spin-exchange relaxation-free (SERF) atomic magnetometer are proposed in this paper. The Larmor precession frequency is measured using the fast Fourier transform (FFT) analysis result of the transient response of the magnetometer under the excitation of a series of the step-changed magnetic field. The spin polarization is extracted from the slow-down factor of the precession frequency. The variation of the spin polarization with different pump light intensities and the distribution of the spin polarization along the direction of the pump light are analyzed, and the experimental results are well consistent with the theoretical predictions. The expanded uncertainties of the experimental results vary from 2% to 11% with the increase of the spin polarization and the reason for this variation is analyzed. The advantage of this method is that it allows the accurate measurement of the spin polarization in the pump beam direction within the SERF regime operating state, and it is unaffected by the large optical depth of the vapor cell.

IEEE Transactions on Instrumentation and Measurement•Apr 27, 2019•67 citations

Measuring Spin Polarization of a Spin-Exchange Relaxation-Free Atomic Magnetometer at Extremely Large Optical Depths

Yanning Ma, Jixi Lu, Ke Yang +5 more

This paper presents a method for measuring the spin polarization of spin-exchange relaxation-free (SERF) atomic magnetometers at extremely large optical depths. Owing to the slowing-down effect, the spin polarization can be extracted by measuring the slowing-down factor extracted from the precession frequency. However, this technique is limited by a significant error in the regime of extremely large optical depths, where the pump beam intensity for achieving the optimized spin polarization of alkali atoms is significantly increased. We observed that the instantaneous precession frequency measured in the regime where the spin-exchange rate is not much larger than the Larmor frequency was no longer a constant but varied with the pump beam intensity. Thus, a method for measuring spin polarization based on the ratio of the precession frequency to the measured instantaneous precession frequency is proposed. Based on the proposed method, the spin polarization at a temperature of 473K and optical depth of 64 is measured. The measurement results were accordant with theoretical analysis. The expanded uncertainties of the experimental results varied between 1.8% and 9.6%. The proposed method is also applicable to other atomic devices operated in the SERF regime with extremely large optical depths, such as co-magnetometers and atomic spin gyroscopes.

IEEE Transactions on Instrumentation and Measurement•Jan 1, 2022•8 citations

Transient Heat Transfer Modeling of SERF Co-Magnetometer Atomic Ensemble Based on the Thermoelectric Analogy Method

Jiaqi Wu, Feng Liu, Lihong Duan +3 more

Bias instability is one of the most critical factors in the performance of spin-exchange relaxation-free (SERF) co-magnetometers. Previous studies on SERF co-magnetometers have shown that changes in the atomic ensemble temperature can lead to variations in the alkali metal atom density, which in turn affect the optical rotation angle and light shift, ultimately influencing the system’s stability. Building on this understanding, this paper introduces the thermoelectric analogy method for the first time in the transient heat transfer analysis of SERF co-magnetometer atomic ensembles. Using this method, the primary factors affecting the atomic ensemble temperature in a SERF co-magnetometer were analyzed, and transient heat transfer models were established for the following processes: the interaction between the non-magnetic electric heating system and the atomic ensemble temperature, laser heating of the atomic ensemble by the optical system, and the effect of environmental temperature changes on the non-magnetic electric heating system. These models were experimentally validated through active temperature variation experiments. The experimental results show that the proposed transient heat transfer models accurately describe the related heat transfer processes of the atomic ensemble, with model fitting accuracy exceeding 98%. This lays a solid foundation for the high-precision closed-loop control of the atomic ensemble temperature in SERF co-magnetometers and provides valuable insights for the structural design and engineering applications of SERF co-magnetometers.

Photonics•Feb 28, 2025•2 citations

Probe beam influence on spin polarization in spin-exchange relaxation-free co-magnetometers

Yao Wei, Xing Li, Yueyang Zhai +4 more

Abstract Spin-exchange relaxation-free (SERF) co-magnetometers have promising applications in both inertial navigation and fundamental physics experiments. However, the fluctuation in the spin polarization caused by the probe beam has a non-negligible influence on the co-magnetometer signal. In this paper, a theoretical model containing three parameters of the probe beam is established by extending the coupled Bloch equation. Based on this model, the influence of probe power density on the transient and steady-state response of the SERF co-magnetometer is analyzed. According to the transient response model, a new measurement method for transverse optical pumping of the probe beam is proposed. Then, for the steady-state response model, a steady-state error suppression method is suggested by adjusting the degree of circular polarization of the probe beam. Eventually, the suppression method is used to refine the SERF co-magnetometer, achieving a suppression rate of 70.31% in transverse electron spin polarization fluctuations, thus improving the co-magnetometer to a stability of 0.0079∘ h−1. To our knowledge, this is better than what has been reported so far.

Journal of Physics D Applied Physics•Feb 20, 2023•5 citations
This paper investigates the atomic spin polarization controllability of spin-exchange relaxation-free co-magnetometers (SERFCMs). This is the first work in the field of controllability analysis for the atomic spin ensembles systems, whose dynamic behaviors of spin polarization are described by the Bloch equations. Based on the Bloch equations, a state-space model of the atomic spin polarization for SERFCM is first established, which belongs to a particular class of nonlinear systems. For this class of nonlinear systems, a novel determination method for the global state controllability is proposed and proved. Then, this method is implemented in the process of controllability analysis on the atomic spin polarization of an actual SERFCM. Moreover, a theoretically feasible and reasonable solution of the control input is proposed under some physical constraints, with whose limitation of realistic conditions, the controller design can be accomplished more practically and more exactly. Finally, the simulation results demonstrate the feasibility and validation of the proposed controllability determination method.
This paper is the first work to innovatively analyze and determine the reachability of atomic spin polarization of Spin-Exchange Relaxation-Free Atomic Magnetometers (SERFAMs), whose dynamic behaviors described by the Bloch equations. Then, it is transformed into a cybernetic model to analyze the reachability. The results show that the degree of freedom of state transition of atomic spin polarization is not consistent with the input dimension. Although this is contrary to the physical intuition, it corresponds to the point of cybernetics. The simulation results verify this conclusion. This work is an interesting case of applying cybernetics to the study of physics, which broadens the way of thinking for the performance analysis of atomic spin polarization system.
The Spin-Exchange Relaxation-Free Comagnetometer (SERFCM) is a new quantum instrument with ultra-high accuracy. Normally, the atomic ensembles of SERFCM operate in an open-loop state, which is not conducive to long-term high-precision measurements. In order to realize closed-loop control of its atomic polarization state, it is necessary to model and analyze the dynamic characteristics of the SERFCM system. In this paper, a Data-driven physical mechanism (DDPM) modeling method is proposed to realize the modeling of the SERFCM, a multi-input multi-output system. First, the state space equations of the SERFCM are established based on the Bloch equation, which are transformed into a discrete transfer function matrix. Then, based on the criterion of least variance in estimation, we realize the modeling of the discrete transfer function matrix using the excitation input data, the measured output data, and the estimated output data. Finally, the simulation results of modeling under different longitudinal magnetic fields confirm the validity of the proposed method. This work enables the online modeling of SERFCM system and facilitates the analysis of the effects of various parameters on the dynamic characteristics.
A novel method to determine the spin polarization and its distribution for a spin-exchange relaxation-free (SERF) atomic magnetometer are proposed in this paper. The Larmor precession frequency is measured using the fast Fourier transform (FFT) analysis result of the transient response of the magnetometer under the excitation of a series of the step-changed magnetic field. The spin polarization is extracted from the slow-down factor of the precession frequency. The variation of the spin polarization with different pump light intensities and the distribution of the spin polarization along the direction of the pump light are analyzed, and the experimental results are well consistent with the theoretical predictions. The expanded uncertainties of the experimental results vary from 2% to 11% with the increase of the spin polarization and the reason for this variation is analyzed. The advantage of this method is that it allows the accurate measurement of the spin polarization in the pump beam direction within the SERF regime operating state, and it is unaffected by the large optical depth of the vapor cell.
This paper presents a method for measuring the spin polarization of spin-exchange relaxation-free (SERF) atomic magnetometers at extremely large optical depths. Owing to the slowing-down effect, the spin polarization can be extracted by measuring the slowing-down factor extracted from the precession frequency. However, this technique is limited by a significant error in the regime of extremely large optical depths, where the pump beam intensity for achieving the optimized spin polarization of alkali atoms is significantly increased. We observed that the instantaneous precession frequency measured in the regime where the spin-exchange rate is not much larger than the Larmor frequency was no longer a constant but varied with the pump beam intensity. Thus, a method for measuring spin polarization based on the ratio of the precession frequency to the measured instantaneous precession frequency is proposed. Based on the proposed method, the spin polarization at a temperature of 473K and optical depth of 64 is measured. The measurement results were accordant with theoretical analysis. The expanded uncertainties of the experimental results varied between 1.8% and 9.6%. The proposed method is also applicable to other atomic devices operated in the SERF regime with extremely large optical depths, such as co-magnetometers and atomic spin gyroscopes.
Bias instability is one of the most critical factors in the performance of spin-exchange relaxation-free (SERF) co-magnetometers. Previous studies on SERF co-magnetometers have shown that changes in the atomic ensemble temperature can lead to variations in the alkali metal atom density, which in turn affect the optical rotation angle and light shift, ultimately influencing the system’s stability. Building on this understanding, this paper introduces the thermoelectric analogy method for the first time in the transient heat transfer analysis of SERF co-magnetometer atomic ensembles. Using this method, the primary factors affecting the atomic ensemble temperature in a SERF co-magnetometer were analyzed, and transient heat transfer models were established for the following processes: the interaction between the non-magnetic electric heating system and the atomic ensemble temperature, laser heating of the atomic ensemble by the optical system, and the effect of environmental temperature changes on the non-magnetic electric heating system. These models were experimentally validated through active temperature variation experiments. The experimental results show that the proposed transient heat transfer models accurately describe the related heat transfer processes of the atomic ensemble, with model fitting accuracy exceeding 98%. This lays a solid foundation for the high-precision closed-loop control of the atomic ensemble temperature in SERF co-magnetometers and provides valuable insights for the structural design and engineering applications of SERF co-magnetometers.
Abstract Spin-exchange relaxation-free (SERF) co-magnetometers have promising applications in both inertial navigation and fundamental physics experiments. However, the fluctuation in the spin polarization caused by the probe beam has a non-negligible influence on the co-magnetometer signal. In this paper, a theoretical model containing three parameters of the probe beam is established by extending the coupled Bloch equation. Based on this model, the influence of probe power density on the transient and steady-state response of the SERF co-magnetometer is analyzed. According to the transient response model, a new measurement method for transverse optical pumping of the probe beam is proposed. Then, for the steady-state response model, a steady-state error suppression method is suggested by adjusting the degree of circular polarization of the probe beam. Eventually, the suppression method is used to refine the SERF co-magnetometer, achieving a suppression rate of 70.31% in transverse electron spin polarization fluctuations, thus improving the co-magnetometer to a stability of 0.0079∘ h−1. To our knowledge, this is better than what has been reported so far.