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

Physical Review Applied

Continuous High-Sensitivity and High-Bandwidth Atomic Magnetometer

Rujie Li, Fred N. Baynes, Andre Nicholas Luiten, Christopher Perrella

Published Dec 23, 2020• 75 citations
Publisher

Abstract

Here we demonstrate an atomic magnetometer that has a bandwidth of more than 100 kHz and a sensitivity of $180\phantom{\rule{0.2em}{0ex}}\mathrm{fT/}\ensuremath{\surd}\mathrm{Hz}$ at a Fourier frequency of 8 Hz, and $0.7\phantom{\rule{0.2em}{0ex}}\mathrm{nT/}\ensuremath{\surd}\mathrm{Hz}$ at 100 kHz. These sensitivity measurements are achieved at geophysically useful magnetic field magnitudes (approximately $50\phantom{\rule{0.2em}{0ex}}\ensuremath{\mu}\mathrm{T}$ inside a three-layer $\ensuremath{\mu}$-metal shield) and are limited by the photon shot noise for frequencies above 8 Hz. This device is based on a nonlinear magneto-optical rotation sensor that is operated with an active feedback to the pump modulation frequency. We present a theoretical description of the response functions of the components in the magnetometer. We show that the range of operation of atomic magnetometers can thus be expanded beyond the conventional high-sensitivity, low-bandwidth domain, to provide a high-linearity, high-bandwidth, and high-sensitivity sensor.

DOI
10.1103/physrevapplied.14.064067

Related papers

Single-Beam Room-Temperature Atomic Magnetometer with Large Bandwidth and Dynamic Range

K. K. George Kurian, Sushree S. Sahoo, Perunthiruthy K. Madhu +1 more

We present a single-beam atomic magnetometer operating at room temperature for the measurement of ac magnetic fields. The magnetometer functions in the nonlinear regime of magneto-optical rotation of ${}^{85}\mathrm{Rb}$ atomic vapor without any buffer gases. We demonstrate a sensitivity of approximately $0.9\phantom{\rule{0.2em}{0ex}}\mathrm{pT}/\sqrt{\mathrm{Hz}}$ at 2 kHz and a large bandwidth of 24 kHz. The dynamic range of measurement is ${10}^{6}$, making the sensor effective even in Earth's field. We present the signal-to-noise and bandwidth characteristics of the system for both shielded and unshielded modes of operation. Moreover, we perform theoretical analysis for the atom-light system for the single-laser-beam configuration. The effect of light intensity and detuning on the magnetometer is studied theoretically as well as experimentally to understand the strengths and limitations of the technique.

arXiv:2209.04249•Physical Review Applied•May 11, 2023•13 citations

Large-scale multipass two-chamber rf atomic magnetometer

D.J. Heilman, Karen L. Sauer, David W. Prescott +4 more

Optically pumped atomic magnetometers are capable of measuring radio-frequency magnetic fields with high sensitivity, but their narrow bandwidth, of the order of 1 kHz, restricts their applications. Further, their full potential is often not realized, with noisy environments or quantum noise curtailing their sensitivity. This study presents a two-chamber atomic magnetometer, with independent control over the tuning field and pumping helicity in each chamber, which addresses both bandwidth and sensitivity limitations. It demonstrates a practical instance of bandwidth expansion, by simultaneous measurement of signals spaced more than 100 kHz apart, at frequencies corresponding to nuclear quadrupole resonance of ammonium nitrate and potassium chlorate, two materials commonly found in improvised explosive devices. It further demonstrates: the intrinsic reduction of common-mode noise, including environmental and probe light-shift noise, down to 2.4 $\mathrm{fT}/\sqrt{\mathrm{Hz}}$, with the use of resonant, but oppositely pumped, atomic chambers; the reduction of photon shot noise down to 28 $\mathrm{aT}/\sqrt{\mathrm{Hz}}$ with the use of 44 probe passes through the two chambers; and the reduction of atom noise down to 34 $\mathrm{aT}/\sqrt{\mathrm{Hz}}$, in agreement with prediction, using a large combined volume, 128 ${\mathrm{cm}}^{3}$, of ${}^{87}\mathrm{Rb}$ atoms. This work underlines the potential sensitivity of these quantum sensors, while exploring the technical limitation, namely the high pump power required, that stands as a barrier to that sensitivity. Further, it marks a significant step towards utilizing atomic magnetometers in applications demanding broader bandwidth or multiplexing, notably simultaneous measurements at far-spaced radio frequencies.

arXiv:2312.10228•Physical Review Applied•Nov 8, 2024•11 citations

High bandwidth three-axis magnetometer based on optically polarized 85 Rb under unshielded environment

Hongying Yang, Ke Zhang, Yanhua Wang +1 more

Abstract In this paper, we demonstrate a three-axis atomic magnetometer based on parametric oscillations, which can measure the three magnetic field components simultaneously and independently. A circularly polarized pump beam is applied to create the spin polarization, and another linearly polarized probe beam is used to detect the dynamics of the polarized spin under a magnetic field. With a closed-loop system to keep the magnetic field in resonance with the atoms, three components of magnetic field are measured by their feedback signals. We achieve a magnetometer sensitivity of 6 pT ( ) −1 , 25 pT ( ) −1 , and 60 pT ( ) −1 along three axes in the frequency range from 100 Hz to 1 kHz with a bandwidth better than 1 kHz under an unshielded environment. Furthermore, this magnetometer is free of optical modulation, which reduces the complexity of experimental setups. The methods we present here provide a prototype all-electrical three-axis atomic magnetometer.

Journal of Physics D Applied Physics•Nov 4, 2019•23 citations

Three-axis closed-loop optically pumped magnetometer operated in the SERF regime

Yeguang Yan, Jixi Lu, Shaowen Zhang +5 more

We propose a three-axis closed-loop optically pumped magnetometer with high sensitivity. The closed-loop magnetometer has a three-axis sensitivity of approximately 30 fT/Hz 1/2 using two orthogonal laser beams for pumping and probing the alkali metal atoms. In the closed-loop mode, the dynamic range is improved from ±5 nT to ±150 nT. The bandwidth is increased from about 100 Hz to over 2 kHz with 10 kHz modulation fields in x - and y -axes and another 6 kHz modulation field along the z -axis. Compared with single-axis or dual-axis magnetometers, the proposed magnetometer not only provides the direction and magnitude of the magnetic field but also has high robustness in a challenging environment. The magnetometer has applications in biomagnetic measurements, magnetic resonance imaging, and fundamental physics.

Optics Express•May 4, 2022•85 citations

Detection of radio-frequency magnetic fields using nonlinear magneto-optical rotation

M. P. Ledbetter, Víctor M. Acosta, Simon Rochester +3 more

We describe a room-temperature alkali-metal atomic magnetometer for detection of small, high-frequency magnetic fields. The magnetometer operates by detecting optical rotation due to the precession of an aligned ground state in the presence of a small oscillating magnetic field. The resonance frequency of the magnetometer can be adjusted to any desired value by tuning the bias magnetic field. Based on experimentally measured signal-to-noise ratio, we demonstrate a sensitivity of $100\phantom{\rule{0.3em}{0ex}}\mathrm{pG}∕\sqrt{\mathrm{Hz}}$ (rms) in a $3.5\text{\ensuremath{-}}\mathrm{cm}$-diameter paraffin coated cell. Assuming detection at the photon shot-noise limit, we project a sensitivity as low as $25\phantom{\rule{0.3em}{0ex}}\mathrm{pG}∕\sqrt{\mathrm{Hz}}$ (rms).

arXiv:physics/0609196•Physical Review A•Feb 8, 2007•67 citations

Sensitive optical atomic magnetometer based on nonlinear magneto-optical rotation

Chris Hovde, Brian Patton, Eric Corsini +2 more

A self-oscillating magnetometer based on nonlinear magneto-optical rotation using amplitude-modulated pump light and unmodulated probe light (AM-NMOR) in 87Rb has been constructed and tested towards a goal of airborne detection of magnetic anomalies. In AM-NMOR, stroboscopic optical pumping via amplitude modulation of the pump beam creates alignment of the ground electronic state of the rubidium atoms. The Larmor precession causes an ac rotation of the polarization of a separate probe beam; the polarization rotation frequency provides a measure of the magnetic field. An anti-relaxation coating on the walls of the atomic vapor cell results in a long lifetime of 56 ms for the alignment, which enables precise measurement of the precession frequency. Light is delivered to the magnetometer by polarization-maintaining optical fibers. Tests of the sensitivity include directly measuring the beat frequency between the magnetometer and a commercial instrument and measurements of Earth's field under magnetically quiet conditions, indicating a sensitivity of at least 5 pT/νHz. Rotating the sensor indicates a heading error of less than 1 nT, limited in part by residual magnetism of the sensor.

arXiv:1003.1531•Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Apr 23, 2010•6 citations
Here we demonstrate an atomic magnetometer that has a bandwidth of more than 100 kHz and a sensitivity of 180fT/\ensuremath√Hz180\phantom{\rule{0.2em}{0ex}}\mathrm{fT/}\ensuremath{\surd}\mathrm{Hz}180fT/\ensuremath√Hz at a Fourier frequency of 8 Hz, and 0.7nT/\ensuremath√Hz0.7\phantom{\rule{0.2em}{0ex}}\mathrm{nT/}\ensuremath{\surd}\mathrm{Hz}0.7nT/\ensuremath√Hz at 100 kHz. These sensitivity measurements are achieved at geophysically useful magnetic field magnitudes (approximately 50\ensuremathμT50\phantom{\rule{0.2em}{0ex}}\ensuremath{\mu}\mathrm{T}50\ensuremathμT inside a three-layer \ensuremathμ\ensuremath{\mu}\ensuremathμ-metal shield) and are limited by the photon shot noise for frequencies above 8 Hz. This device is based on a nonlinear magneto-optical rotation sensor that is operated with an active feedback to the pump modulation frequency. We present a theoretical description of the response functions of the components in the magnetometer. We show that the range of operation of atomic magnetometers can thus be expanded beyond the conventional high-sensitivity, low-bandwidth domain, to provide a high-linearity, high-bandwidth, and high-sensitivity sensor.
We present a single-beam atomic magnetometer operating at room temperature for the measurement of ac magnetic fields. The magnetometer functions in the nonlinear regime of magneto-optical rotation of 85Rb{}^{85}\mathrm{Rb}85Rb atomic vapor without any buffer gases. We demonstrate a sensitivity of approximately 0.9pT/Hz0.9\phantom{\rule{0.2em}{0ex}}\mathrm{pT}/\sqrt{\mathrm{Hz}}0.9pT/Hz​ at 2 kHz and a large bandwidth of 24 kHz. The dynamic range of measurement is 106{10}^{6}106, making the sensor effective even in Earth's field. We present the signal-to-noise and bandwidth characteristics of the system for both shielded and unshielded modes of operation. Moreover, we perform theoretical analysis for the atom-light system for the single-laser-beam configuration. The effect of light intensity and detuning on the magnetometer is studied theoretically as well as experimentally to understand the strengths and limitations of the technique.
Optically pumped atomic magnetometers are capable of measuring radio-frequency magnetic fields with high sensitivity, but their narrow bandwidth, of the order of 1 kHz, restricts their applications. Further, their full potential is often not realized, with noisy environments or quantum noise curtailing their sensitivity. This study presents a two-chamber atomic magnetometer, with independent control over the tuning field and pumping helicity in each chamber, which addresses both bandwidth and sensitivity limitations. It demonstrates a practical instance of bandwidth expansion, by simultaneous measurement of signals spaced more than 100 kHz apart, at frequencies corresponding to nuclear quadrupole resonance of ammonium nitrate and potassium chlorate, two materials commonly found in improvised explosive devices. It further demonstrates: the intrinsic reduction of common-mode noise, including environmental and probe light-shift noise, down to 2.4 fT/Hz\mathrm{fT}/\sqrt{\mathrm{Hz}}fT/Hz​, with the use of resonant, but oppositely pumped, atomic chambers; the reduction of photon shot noise down to 28 aT/Hz\mathrm{aT}/\sqrt{\mathrm{Hz}}aT/Hz​ with the use of 44 probe passes through the two chambers; and the reduction of atom noise down to 34 aT/Hz\mathrm{aT}/\sqrt{\mathrm{Hz}}aT/Hz​, in agreement with prediction, using a large combined volume, 128 cm3{\mathrm{cm}}^{3}cm3, of 87Rb{}^{87}\mathrm{Rb}87Rb atoms. This work underlines the potential sensitivity of these quantum sensors, while exploring the technical limitation, namely the high pump power required, that stands as a barrier to that sensitivity. Further, it marks a significant step towards utilizing atomic magnetometers in applications demanding broader bandwidth or multiplexing, notably simultaneous measurements at far-spaced radio frequencies.
Abstract In this paper, we demonstrate a three-axis atomic magnetometer based on parametric oscillations, which can measure the three magnetic field components simultaneously and independently. A circularly polarized pump beam is applied to create the spin polarization, and another linearly polarized probe beam is used to detect the dynamics of the polarized spin under a magnetic field. With a closed-loop system to keep the magnetic field in resonance with the atoms, three components of magnetic field are measured by their feedback signals. We achieve a magnetometer sensitivity of 6 pT ( ) −1 , 25 pT ( ) −1 , and 60 pT ( ) −1 along three axes in the frequency range from 100 Hz to 1 kHz with a bandwidth better than 1 kHz under an unshielded environment. Furthermore, this magnetometer is free of optical modulation, which reduces the complexity of experimental setups. The methods we present here provide a prototype all-electrical three-axis atomic magnetometer.
We propose a three-axis closed-loop optically pumped magnetometer with high sensitivity. The closed-loop magnetometer has a three-axis sensitivity of approximately 30 fT/Hz 1/2 using two orthogonal laser beams for pumping and probing the alkali metal atoms. In the closed-loop mode, the dynamic range is improved from ±5 nT to ±150 nT. The bandwidth is increased from about 100 Hz to over 2 kHz with 10 kHz modulation fields in x - and y -axes and another 6 kHz modulation field along the z -axis. Compared with single-axis or dual-axis magnetometers, the proposed magnetometer not only provides the direction and magnitude of the magnetic field but also has high robustness in a challenging environment. The magnetometer has applications in biomagnetic measurements, magnetic resonance imaging, and fundamental physics.
We describe a room-temperature alkali-metal atomic magnetometer for detection of small, high-frequency magnetic fields. The magnetometer operates by detecting optical rotation due to the precession of an aligned ground state in the presence of a small oscillating magnetic field. The resonance frequency of the magnetometer can be adjusted to any desired value by tuning the bias magnetic field. Based on experimentally measured signal-to-noise ratio, we demonstrate a sensitivity of 100pG∕Hz100\phantom{\rule{0.3em}{0ex}}\mathrm{pG}∕\sqrt{\mathrm{Hz}}100pG∕Hz​ (rms) in a $3.5\text{\ensuremath{-}}\mathrm{cm}$-diameter paraffin coated cell. Assuming detection at the photon shot-noise limit, we project a sensitivity as low as 25pG∕Hz25\phantom{\rule{0.3em}{0ex}}\mathrm{pG}∕\sqrt{\mathrm{Hz}}25pG∕Hz​ (rms).
A self-oscillating magnetometer based on nonlinear magneto-optical rotation using amplitude-modulated pump light and unmodulated probe light (AM-NMOR) in 87Rb has been constructed and tested towards a goal of airborne detection of magnetic anomalies. In AM-NMOR, stroboscopic optical pumping via amplitude modulation of the pump beam creates alignment of the ground electronic state of the rubidium atoms. The Larmor precession causes an ac rotation of the polarization of a separate probe beam; the polarization rotation frequency provides a measure of the magnetic field. An anti-relaxation coating on the walls of the atomic vapor cell results in a long lifetime of 56 ms for the alignment, which enables precise measurement of the precession frequency. Light is delivered to the magnetometer by polarization-maintaining optical fibers. Tests of the sensitivity include directly measuring the beat frequency between the magnetometer and a commercial instrument and measurements of Earth's field under magnetically quiet conditions, indicating a sensitivity of at least 5 pT/νHz. Rotating the sensor indicates a heading error of less than 1 nT, limited in part by residual magnetism of the sensor.