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

arXiv:0708.1012 · Physical Review A

Spin-exchange-relaxation-free magnetometry with Cs vapor

M. P. Ledbetter, Igor Savukov, Víctor M. Acosta, Dmitry Budker, Michael V. Romalis

Published Mar 13, 2008• 400 citations
arXivHTMLPDF

Abstract

We describe a Cs atomic magnetometer operating in the spin-exchange-relaxation-free (SERF) regime. With a vapor cell temperature of $103\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}$ we achieve intrinsic magnetic resonance widths $\ensuremath{\Delta}B=17\text{ }\ensuremath{\mu}\text{G}$ corresponding to an electron spin-relaxation rate of $300\text{ }{\text{s}}^{\ensuremath{-}1}$ when the spin-exchange rate is ${\ensuremath{\Gamma}}_{\text{SE}}=14\text{ }000\text{ }{\text{s}}^{\ensuremath{-}1}$. We also observe an interesting narrowing effect due to diffusion. Signal-to-noise measurements yield a sensitivity of about $400\text{ }\text{pG}/\sqrt{\text{Hz}}$. Based on photon shot noise, we project a sensitivity of $40\text{ }\text{pG}/\sqrt{\text{Hz}}$. A theoretical optimization of the magnetometer indicates sensitivities on the order of $2\text{ }\text{pG}/\sqrt{\text{Hz}}$ should be achievable in a $1\text{ }{\text{cm}}^{3}$ volume. Because Cs has a higher saturated vapor pressure than other alkali metals, SERF magnetometers using Cs atoms are particularly attractive in applications requiring lower temperatures.

DOI
10.1103/physreva.77.033408

Related papers

Study of resonance curve width in Cs vapor magnetometer

Sun Weimin

A new magnetometer with Cs vapor in the spin exchange relaxation free(SERF) regime is described.Cs has a higher saturated vapor pressure than other alkali metals;so cesium SERF magnetometer is particularly attractive in applications that require lower power dissipation.Four factors affect atomic transverse relaxations in the SERF magnetometer,including collisions and diffusions among Cs,N2 and He,laser pumping and detecting processes;the buffer gas pressure of He that affects the relaxation is calculated and discussed emphatically in theory at 105 ℃,the result shows that the optimum buffer gas pressure is 350×133.3 Pa.Under the optimum pressure,the polarized spectrum linewidth as the function of the cell temperature is discussed briefly.It is found the least linewidth is only 3.7 Hz corresponding to the electric spin relaxation rate of 278 s-1 at 105 ℃.The result provides a help to increase the sensitivity of the magnetometer with Cs vapor.

Journal of Optoelectronics·laser•Jan 1, 2010•0 citations

Study of optimum pumping intensity at Cs vapor magnetometer

Junhai Zhang, Feng Wang, Jiuxing Li +1 more

The paper describes a new magnetometer with Cs vapor in the spin exchange relaxation free (SERF) regime. Because cesium atom has a higher saturated vapor pressure than other alkali metallic atoms, so the magnetometer has required lower operated temperature. We have discussed the effect of different pumping intensities on the polarization and the pumping rate at 105°C in theory; and the result shows out the magnetometer will have maximum sensitivity when the pumping intensity is 52mW/cm2. Taking into account all relaxations including collision relaxations, diffusion relaxation and pumping relaxation from pump light, we find the relaxation rate will be about 6Hz for the cesium magnetometer with SERF.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 13, 2010•1 citation

Study of the vapor cell size at high sensitive Cs magnetometer

Jiuxing Li, Qiang Liu, Qingmeng Li +2 more

The spin-exchange relaxation free (SERF) magnetometers are the most sensitive atomic magnetometers, the optimum sensitivity of which is on the order of 0.1 fTHz-1/2. The size of the vapor cell is important in the miniaturization of the Cs vapor magnetometer, for it determining other components'. The more importance is dependence of the spin-destruction rate, which is the maximum relaxation rate in the SERF regime. This paper presents the design of the vapor cell at Cs SERF magnetometers and the discussion of the highest sensitivity achieved in different sizes.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Nov 23, 2011•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

The Characterization of Atomic Vapor Cells for High-Sensitivity Magnetic Field Measurements in SERF Regime

Murat Salim Karabinaoğlu, Berfin Muhlise Caklı, Mehmet Hüseyin Sevim

Nowadays, quantum sensor research is a very interesting and popular topic. High-sensitivity magnetic field measurements using quantum sensors have evolved into the most sensitive magnetic field sensor category today with the invention of atomic magnetometers operating in the spin-exchange relaxation-free (SERF) regime. This letter was prepared to investigate the magnetic field sensitivity changes depending on the buffer gas, temperature, and laser intensity using indigenously produced atomic vapor cells. In addition, the aim was to determine the optimum operating conditions of the atomic magnetometer operating in the SERF regime. As a result, the resonance linewidth and signal-to-noise ratio were measured, and the minimum detectable magnetic field was calculated. According to the obtained results, the lowest magnetic field for Cells I–III was measured as 5.12, 4.21, and 4.81 pT, respectively. The lowest magnetic field of all conditions was obtained in vapor cell (Cell-II) at 100 °C with 5 mW laser intensity. As a result, it has been experimentally proven that under the same conditions, increasing the buffer gas pressure in vapor cells can narrow the resonance linewidth, and the magnetic field sensitivity can be improved by increasing the laser intensity applied to the vapor cells.

IEEE Sensors Letters•Feb 24, 2025•5 citations

A large sample study of spin relaxation and magnetometric sensitivity of paraffin-coated Cs vapor cells

N. Castagna, G. Bison, Giovanni Di Domenico +5 more

Abstract We have manufactured more than 250 nominally identical paraffin-coated Cs vapor cells (30 mm diameter bulbs) for multi-channel atomic magnetometer applications. We describe our dedicated cell characterization apparatus. For each cell we have determined the intrinsic longitudinal, Γ01, and transverse, Γ02, relaxation rates. Our best cell shows Γ01/2π ≈ 0.5 Hz, and Γ02/2π ≈ 2 Hz. We find a strong correlation of both relaxation rates which we explain in terms of reservoir and spin exchange relaxation. For each cell we have determined the optimal combination of rf and laser powers which yield the highest sensitivity to magnetic field changes. Out of all produced cells, 90 % are found to have magnetometric sensitivities in the range of 9 to 30 fT / √ Hz. Noise analysis shows that the magnetometers operated with such cells have a sensitivity close to the fundamental photon shot noise limit. 1

•Nov 10, 2009•64 citations
We describe a Cs atomic magnetometer operating in the spin-exchange-relaxation-free (SERF) regime. With a vapor cell temperature of 103 \ifmmode∘\else\textdegree\fiC103\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}103 \ifmmode∘\else\textdegree\fiC we achieve intrinsic magnetic resonance widths \ensuremathΔB=17 \ensuremathμG\ensuremath{\Delta}B=17\text{ }\ensuremath{\mu}\text{G}\ensuremathΔB=17 \ensuremathμG corresponding to an electron spin-relaxation rate of 300 s\ensuremath−1300\text{ }{\text{s}}^{\ensuremath{-}1}300 s\ensuremath−1 when the spin-exchange rate is \ensuremathΓSE=14 000 s\ensuremath−1{\ensuremath{\Gamma}}_{\text{SE}}=14\text{ }000\text{ }{\text{s}}^{\ensuremath{-}1}\ensuremathΓSE​=14 000 s\ensuremath−1. We also observe an interesting narrowing effect due to diffusion. Signal-to-noise measurements yield a sensitivity of about 400 pG/Hz400\text{ }\text{pG}/\sqrt{\text{Hz}}400 pG/Hz​. Based on photon shot noise, we project a sensitivity of 40 pG/Hz40\text{ }\text{pG}/\sqrt{\text{Hz}}40 pG/Hz​. A theoretical optimization of the magnetometer indicates sensitivities on the order of 2 pG/Hz2\text{ }\text{pG}/\sqrt{\text{Hz}}2 pG/Hz​ should be achievable in a 1 cm31\text{ }{\text{cm}}^{3}1 cm3 volume. Because Cs has a higher saturated vapor pressure than other alkali metals, SERF magnetometers using Cs atoms are particularly attractive in applications requiring lower temperatures.
A new magnetometer with Cs vapor in the spin exchange relaxation free(SERF) regime is described.Cs has a higher saturated vapor pressure than other alkali metals;so cesium SERF magnetometer is particularly attractive in applications that require lower power dissipation.Four factors affect atomic transverse relaxations in the SERF magnetometer,including collisions and diffusions among Cs,N2 and He,laser pumping and detecting processes;the buffer gas pressure of He that affects the relaxation is calculated and discussed emphatically in theory at 105 ℃,the result shows that the optimum buffer gas pressure is 350×133.3 Pa.Under the optimum pressure,the polarized spectrum linewidth as the function of the cell temperature is discussed briefly.It is found the least linewidth is only 3.7 Hz corresponding to the electric spin relaxation rate of 278 s-1 at 105 ℃.The result provides a help to increase the sensitivity of the magnetometer with Cs vapor.
The paper describes a new magnetometer with Cs vapor in the spin exchange relaxation free (SERF) regime. Because cesium atom has a higher saturated vapor pressure than other alkali metallic atoms, so the magnetometer has required lower operated temperature. We have discussed the effect of different pumping intensities on the polarization and the pumping rate at 105°C in theory; and the result shows out the magnetometer will have maximum sensitivity when the pumping intensity is 52mW/cm2. Taking into account all relaxations including collision relaxations, diffusion relaxation and pumping relaxation from pump light, we find the relaxation rate will be about 6Hz for the cesium magnetometer with SERF.
The spin-exchange relaxation free (SERF) magnetometers are the most sensitive atomic magnetometers, the optimum sensitivity of which is on the order of 0.1 fTHz-1/2. The size of the vapor cell is important in the miniaturization of the Cs vapor magnetometer, for it determining other components'. The more importance is dependence of the spin-destruction rate, which is the maximum relaxation rate in the SERF regime. This paper presents the design of the vapor cell at Cs SERF magnetometers and the discussion of the highest sensitivity achieved in different sizes.
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.
Nowadays, quantum sensor research is a very interesting and popular topic. High-sensitivity magnetic field measurements using quantum sensors have evolved into the most sensitive magnetic field sensor category today with the invention of atomic magnetometers operating in the spin-exchange relaxation-free (SERF) regime. This letter was prepared to investigate the magnetic field sensitivity changes depending on the buffer gas, temperature, and laser intensity using indigenously produced atomic vapor cells. In addition, the aim was to determine the optimum operating conditions of the atomic magnetometer operating in the SERF regime. As a result, the resonance linewidth and signal-to-noise ratio were measured, and the minimum detectable magnetic field was calculated. According to the obtained results, the lowest magnetic field for Cells I–III was measured as 5.12, 4.21, and 4.81 pT, respectively. The lowest magnetic field of all conditions was obtained in vapor cell (Cell-II) at 100 °C with 5 mW laser intensity. As a result, it has been experimentally proven that under the same conditions, increasing the buffer gas pressure in vapor cells can narrow the resonance linewidth, and the magnetic field sensitivity can be improved by increasing the laser intensity applied to the vapor cells.
Abstract We have manufactured more than 250 nominally identical paraffin-coated Cs vapor cells (30 mm diameter bulbs) for multi-channel atomic magnetometer applications. We describe our dedicated cell characterization apparatus. For each cell we have determined the intrinsic longitudinal, Γ01, and transverse, Γ02, relaxation rates. Our best cell shows Γ01/2π ≈ 0.5 Hz, and Γ02/2π ≈ 2 Hz. We find a strong correlation of both relaxation rates which we explain in terms of reservoir and spin exchange relaxation. For each cell we have determined the optimal combination of rf and laser powers which yield the highest sensitivity to magnetic field changes. Out of all produced cells, 90 % are found to have magnetometric sensitivities in the range of 9 to 30 fT / √ Hz. Noise analysis shows that the magnetometers operated with such cells have a sensitivity close to the fundamental photon shot noise limit. 1