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

International Conference on Control and Robotics (ICCR)

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

Ruigang Wang, Zhuo Wang, Chong Ma, Shun Li, Tiexiao Xu, Mengliang Fang, Zehua Liu

Published Dec 2, 2022• 1 citation
Publisher

Abstract

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.

DOI
10.1109/iccr55715.2022.10053892

Related papers

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

Zhuo Wang, Sixun Liu, Ruigang Wang +4 more

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.

IEEE/CAA Journal of Automatica Sinica•Dec 10, 2021•33 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

Measurement of Equilibrium Spin Polarization in Spin-Exchange Relaxation-Free Atomic Magnetometers via the Steady-State Response to the Triaxial Magnetic Field

Faming Wang, Xiujie Fang, Bozheng Xing +5 more

This study proposes an in situ method for measuring the equilibrium spin polarization and its longitudinal spatial distribution in a spin-exchange relaxation-free (SERF) atomic magnetometer. The total relaxation rate was determined by analyzing the steady-state response of the magnetometer to the triaxial magnetic field. The transfer coefficient between spin polarization along the probe beam axis and the steady-state response was derived from the optical depth of the probe light and the incident/transmitted power through the vapor cell. By applying a DC magnetic field along the sensitive axis and combining the total relaxation rate with the transfer coefficient, the equilibrium spin polarization value under zero-field conditions was obtained. The equilibrium spin polarization distribution along the pump beam propagation direction was measured, showing consistent trends with simulation results, with a maximum relative error of less than 5%. The expanded uncertainty of the proposed equilibrium spin polarization measurement method ranges from 0.8% to 9.7%. The advantages of this method include no requirement for additional optical field or magnetic field modulation, immunity to temperature and temperature gradients, and the capability to directly determine the equilibrium spin polarization value.

IEEE Transactions on Instrumentation and Measurement•Jan 1, 2025•7 citations

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

A Fast Identification on the Spin-Exchange Relaxation-Free Regime of Atomic Magnetometer Exploiting Measurement on Gyromagnetic Ratio

Xue Zhang, Jianan Qin, Yanzhang Wang +1 more

Spin-exchange relaxation-free (SERF) atomic magnetometers seem to be the state-of-the-art magnetic sensors today as they have achieved a sensitivity of femtotesla in the elimination of broadening contribution of spin-exchange collisions operated in the mode of SERF regime. In order to extend the practicability of SERF atomic magnetometry in superb performances in a movable platform, ensuring and testing the working status of alkali atoms are of great importance. Given the fact that in the premise of SERF regime, the linewidth of magnetic resonance would be narrowing down and the precession frequency would become a constant fractional value of the Larmor frequency for alkali atoms, we measure the gyromagnetic ratio of weakly polarized alkali-metal vapor by yielding the damped oscillating curves and fitting measured increments of frequency and magnetic field to identify the working regime of alkali atoms in a fast and straightforward manner. The experimental results have good agreements with theoretical analysis and simulation, and the whole measurement process lasts milliseconds with relatively measured error ±1% in the temperature range of T = 156 °C-184 °C. To testify the validity of the innovation, magnetic resonance line is obtained in the same condition proffering the width comparative with the outcome from simulation, indicating the spin-exchange broadening has been eliminated, presenting the same conclusion with innovation, and providing systematic sensitivity 30 fT/Hz1/2.

IEEE Transactions on Instrumentation and Measurement•Aug 24, 2018•35 citations

A fast determination method for identifying the spin exchange relaxation free regime of atomic magnetometer

Yanzhang Wang, Xue Zhang, Jianan Qin +1 more

Spin-exchange-relaxation-free (SERF) atomic magnetometer is the most sensitive magnetic detector in the world at present due to the fact that the broadening of spin-exchange collision is eliminated by operating at high alkali-mental density and low magnetic field. On that condition, the precession frequency of high-density alkali vapor becomes a constant fractional value of Larmor frequency, and the width of magnetic-resonance line gets narrower. This paper analyzes the principle of SERF regime and proposes an innovation based on measuring the slowing-down Larmor frequency directly instead of the complicated conventional method based on the width of magnetic resonance line. We calculated and simulated the slowing-down precession frequency and linewidth of magnetic resonance on certain conditions. The experimental results have verified that the method is valid to identify the regime of SERF of atomic magnetometer via detecting the slowing-down precession frequency.

Proceedings of IEEE Sensors/Proceedings of IEEE Sensors ...•Oct 1, 2016•1 citation
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.
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.
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 study proposes an in situ method for measuring the equilibrium spin polarization and its longitudinal spatial distribution in a spin-exchange relaxation-free (SERF) atomic magnetometer. The total relaxation rate was determined by analyzing the steady-state response of the magnetometer to the triaxial magnetic field. The transfer coefficient between spin polarization along the probe beam axis and the steady-state response was derived from the optical depth of the probe light and the incident/transmitted power through the vapor cell. By applying a DC magnetic field along the sensitive axis and combining the total relaxation rate with the transfer coefficient, the equilibrium spin polarization value under zero-field conditions was obtained. The equilibrium spin polarization distribution along the pump beam propagation direction was measured, showing consistent trends with simulation results, with a maximum relative error of less than 5%. The expanded uncertainty of the proposed equilibrium spin polarization measurement method ranges from 0.8% to 9.7%. The advantages of this method include no requirement for additional optical field or magnetic field modulation, immunity to temperature and temperature gradients, and the capability to directly determine the equilibrium spin polarization value.
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.
Spin-exchange relaxation-free (SERF) atomic magnetometers seem to be the state-of-the-art magnetic sensors today as they have achieved a sensitivity of femtotesla in the elimination of broadening contribution of spin-exchange collisions operated in the mode of SERF regime. In order to extend the practicability of SERF atomic magnetometry in superb performances in a movable platform, ensuring and testing the working status of alkali atoms are of great importance. Given the fact that in the premise of SERF regime, the linewidth of magnetic resonance would be narrowing down and the precession frequency would become a constant fractional value of the Larmor frequency for alkali atoms, we measure the gyromagnetic ratio of weakly polarized alkali-metal vapor by yielding the damped oscillating curves and fitting measured increments of frequency and magnetic field to identify the working regime of alkali atoms in a fast and straightforward manner. The experimental results have good agreements with theoretical analysis and simulation, and the whole measurement process lasts milliseconds with relatively measured error ±1% in the temperature range of T = 156 °C-184 °C. To testify the validity of the innovation, magnetic resonance line is obtained in the same condition proffering the width comparative with the outcome from simulation, indicating the spin-exchange broadening has been eliminated, presenting the same conclusion with innovation, and providing systematic sensitivity 30 fT/Hz1/2.
Spin-exchange-relaxation-free (SERF) atomic magnetometer is the most sensitive magnetic detector in the world at present due to the fact that the broadening of spin-exchange collision is eliminated by operating at high alkali-mental density and low magnetic field. On that condition, the precession frequency of high-density alkali vapor becomes a constant fractional value of Larmor frequency, and the width of magnetic-resonance line gets narrower. This paper analyzes the principle of SERF regime and proposes an innovation based on measuring the slowing-down Larmor frequency directly instead of the complicated conventional method based on the width of magnetic resonance line. We calculated and simulated the slowing-down precession frequency and linewidth of magnetic resonance on certain conditions. The experimental results have verified that the method is valid to identify the regime of SERF of atomic magnetometer via detecting the slowing-down precession frequency.