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:2306.16924 · Physical Review Applied

Ultimate parameters of an all-optical MX resonance in Cs in ultraweak magnetic field

Mikhail V. Petrenko, Anatoly S. Pazgalev, Anton K. Vershovskii

Published Sep 29, 2023• 1 citation
arXivHTMLPDF

Abstract

We present the results of studying the parameters of the magnetic ${M}_{X}$ resonance in an all-optical sensor built according to the two-beam Bell-Bloom scheme in nonzero ultraweak magnetic fields in which the effects of spin-exchange broadening suppression are partially manifested. We report on the features of the resonance under these conditions. We also optimize the resonance parameters to achieve maximum sensitivity in magnetoencephalographic sensors. We demonstrate an improvement in the ultimate achievable sensitivity of an all-optical ${M}_{X}$ sensor by a factor of 4 or more, which in our experiment corresponds to a decrease from 13 to $3\phantom{\rule{0.2em}{0ex}}{\text{fT/Hz}}^{1/2}$ in a volume of $0.13\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{3}$. We also report the effect of incomplete suppression of spin-exchange broadening under conditions of strong transverse modulated optical pumping, and propose a semiempirical model to describe it.

DOI
10.1103/physrevapplied.20.034074

Related papers

All-Optical Magnetometric Sensor for Magnetoencephalography and Ultralow Field Tomography

Anton K. Vershovskii, Anatoly S. Pazgalev, Mikhail V. Petrenko

Abstract A variant of the scheme of a magnetometric sensor based on cesium atomic vapor is proposed and experimentally investigated. The sensor uses magnetic resonance excitation by modulated light of an hyperfine optical pumping that is transverse to the magnetic field. It is shown that, for a cell with a volume of 0.125 cm3, the variational sensitivity of such a scheme, estimated from the ratio of the steepness of the signal in the center of the magnetic resonance to the shot noise of the detecting radiation, reaches a level of <10 fT/Hz1/2 in the frequency band width of the order of 850 Hz. The sensor, which does not emit radio frequency fields, is designed for use in magnetoencephalographic complexes. Possible ways to improve the performance of the scheme for detecting relatively fast (~4.2 kHz in a field of 0.1 mT) signals of the precession of proton magnetic moments in promising ultra-weak field tomography schemes are considered.

Technical Physics Letters•Sep 1, 2020•12 citations

Методы возбуждения параметрического резонанса в схеме оптического магнитометрического датчика

Anton K. Vershovskii, М.В. Петренко

An experimental comparison of the methods for modulating the parameters of resonant transverse to the external magnetic field pumping radiation in a two-beam optical magnetometric sensor (so called Bell-Bloom scheme) is carried out, as well as a comparison of these methods with the standard method of radio-frequency excitation of magnetic resonance under conditions of strong laser pumping. It is shown that although the standard method allows one to achieve a greater suppression of the spin-exchange broadening of the magnetic resonance line by pumping light, the Bell-Bloom scheme has advantages that make it possible to obtain similar sensitivity values upon modulation of both the intensity and polarization of the pump light; at the same time, the Bell-Bloom scheme is potentially characterized by higher speed, which is essential for the problems of magnetoencephalography and ultra-low field magnetic resonance imaging.

Журнал технической физики•Jan 1, 2021•3 citations

Three-Level Approximation upon Calculation of Parameters of Optically Detected Magnetic Resonance under the Conditions of Strong Laser Pumping

Anton K. Vershovskii, Mikhail V. Petrenko

Abstract An algorithm of approximate solution of an essentially nonlinear problem of parameters of optically detected magnetic resonance in the ground state of alkali atoms in an optically dense medium under the conditions of strong narrow-band optical pumping that induces transparency of atomic medium and partial suppression of spin-exchange broadening is proposed. Straightforward solution of the Liouville’s equation is complicated in this case by the fact that relaxation time of each of the levels of the hyperfine and Zeeman structures of the ground state is determined by populations of all other levels, which results in the necessity of solving a self-consistent problem in a multilevel system and requires using supercomputers, as a rule. In the present work, approximations that allow substantially simplifying and accelerating calculation are proposed. A two-beam MX-scheme of a magnetometric sensor is used as an example to compare the results of calculations with experimental data.

Optics and Spectroscopy•May 1, 2021•3 citations

Anomalous suppression of spin-exchange relaxation in alignment signals in cesium in ultraweak magnetic fields

M. V. Petrenko, Anton K. Vershovskii

The results of a study of the dynamics of atomic moments alignment in cesium under optical pumping by linearly polarized resonant light in ultra-weak magnetic field are presented. It is shown that there are alignment components whose relaxation does not depend on spin-exchange broadening. The effect of suppression of spin-exchange relaxation in zero magnetic fields is detected, which is similar in its manifestations to the SERF (Spin-Exchange Relaxation Free) effect observed in orientation signals. This observation is interesting from the standpoint of general theory, since the law of conservation of angular momentum responsible for maintaining orientation in the SERF mode should not guarantee the preservation of alignment under the same conditions. A comparison with theoretically calculated parameters of SERF resonances in orientation is given. A qualitative explanation of the observed effect is presented.

arXiv:2501.11722•Physical Review A•Jul 14, 2025•3 citations

Light-narrowed optically pumped Mx magnetometer with a miniaturized Cs cell

Theo Scholtes, V. Schultze, R.P.J. IJsselsteijn +2 more

We demonstrate a way of operating an optically pumped magnetometer with miniaturized cesium cell using the light-narrowing effect. The magnetometer setup shows improvement of shot-noise-limited sensitivity ($42\phantom{\rule{0.16em}{0ex}}\mathrm{fT}/\sqrt{\mathrm{Hz}}$ in a cell of only $9.3\phantom{\rule{0.16em}{0ex}}{\mathrm{mm}}^{3}$ volume) due to the suppression of spin-exchange relaxation to a large extent and the use of a strikingly increased fraction of alkali-metal atoms for signal generation, working even in $\ensuremath{\mu}\mathrm{T}$ magnetic fields, by using only a single high-intensity laser beam both for pumping and probing of atomic spins.

Physical Review A•Oct 12, 2011•120 citations

Measurement Sensitivity Improvement of All-Optical Atomic Spin Magnetometer by Suppressing Noises

Xiyuan Chen, Hong Zhang, Sheng Zou

Quantum manipulation technology and photoelectric detection technology have jointly facilitated the rapid development of ultra-sensitive atomic spin magnetometers. To improve the output signal and sensitivity of the spin-exchange-relaxation-free (SERF) atomic spin magnetometer, the noises influencing on the output signal and the sensitivity were analyzed, and the corresponding noise suppression methods were presented. The magnetic field noises, including the residual magnetic field noise and the light shift noise, were reduced to approximately zero by employing the magnetic field compensation method and by adjusting the frequency of the pump beam, respectively. With respect to the operation temperature, the simulation results showed that the temperature of the potassium atomic spin magnetometer realizing the spin-exchange relaxation-free regime was 180 °C. Moreover, the fluctuation noises of the frequency and the power were suppressed by using the frequency and the power stable systems. The experimental power stability results showed that the light intensity stability was enhanced 10%. Contrast experiments on the sensitivity were carried out to demonstrate the validity of the suppression methods. Finally, a sensitivity of 13 fT/Hz(1/2) was successfully achieved by suppressing noises and optimizing parameters.

Sensors•Jun 17, 2016•9 citations
We present the results of studying the parameters of the magnetic MX{M}_{X}MX​ resonance in an all-optical sensor built according to the two-beam Bell-Bloom scheme in nonzero ultraweak magnetic fields in which the effects of spin-exchange broadening suppression are partially manifested. We report on the features of the resonance under these conditions. We also optimize the resonance parameters to achieve maximum sensitivity in magnetoencephalographic sensors. We demonstrate an improvement in the ultimate achievable sensitivity of an all-optical MX{M}_{X}MX​ sensor by a factor of 4 or more, which in our experiment corresponds to a decrease from 13 to 3fT/Hz1/23\phantom{\rule{0.2em}{0ex}}{\text{fT/Hz}}^{1/2}3fT/Hz1/2 in a volume of 0.13cm30.13\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{3}0.13cm3. We also report the effect of incomplete suppression of spin-exchange broadening under conditions of strong transverse modulated optical pumping, and propose a semiempirical model to describe it.
Abstract A variant of the scheme of a magnetometric sensor based on cesium atomic vapor is proposed and experimentally investigated. The sensor uses magnetic resonance excitation by modulated light of an hyperfine optical pumping that is transverse to the magnetic field. It is shown that, for a cell with a volume of 0.125 cm3, the variational sensitivity of such a scheme, estimated from the ratio of the steepness of the signal in the center of the magnetic resonance to the shot noise of the detecting radiation, reaches a level of <10 fT/Hz1/2 in the frequency band width of the order of 850 Hz. The sensor, which does not emit radio frequency fields, is designed for use in magnetoencephalographic complexes. Possible ways to improve the performance of the scheme for detecting relatively fast (~4.2 kHz in a field of 0.1 mT) signals of the precession of proton magnetic moments in promising ultra-weak field tomography schemes are considered.
An experimental comparison of the methods for modulating the parameters of resonant transverse to the external magnetic field pumping radiation in a two-beam optical magnetometric sensor (so called Bell-Bloom scheme) is carried out, as well as a comparison of these methods with the standard method of radio-frequency excitation of magnetic resonance under conditions of strong laser pumping. It is shown that although the standard method allows one to achieve a greater suppression of the spin-exchange broadening of the magnetic resonance line by pumping light, the Bell-Bloom scheme has advantages that make it possible to obtain similar sensitivity values upon modulation of both the intensity and polarization of the pump light; at the same time, the Bell-Bloom scheme is potentially characterized by higher speed, which is essential for the problems of magnetoencephalography and ultra-low field magnetic resonance imaging.
Abstract An algorithm of approximate solution of an essentially nonlinear problem of parameters of optically detected magnetic resonance in the ground state of alkali atoms in an optically dense medium under the conditions of strong narrow-band optical pumping that induces transparency of atomic medium and partial suppression of spin-exchange broadening is proposed. Straightforward solution of the Liouville’s equation is complicated in this case by the fact that relaxation time of each of the levels of the hyperfine and Zeeman structures of the ground state is determined by populations of all other levels, which results in the necessity of solving a self-consistent problem in a multilevel system and requires using supercomputers, as a rule. In the present work, approximations that allow substantially simplifying and accelerating calculation are proposed. A two-beam MX-scheme of a magnetometric sensor is used as an example to compare the results of calculations with experimental data.
The results of a study of the dynamics of atomic moments alignment in cesium under optical pumping by linearly polarized resonant light in ultra-weak magnetic field are presented. It is shown that there are alignment components whose relaxation does not depend on spin-exchange broadening. The effect of suppression of spin-exchange relaxation in zero magnetic fields is detected, which is similar in its manifestations to the SERF (Spin-Exchange Relaxation Free) effect observed in orientation signals. This observation is interesting from the standpoint of general theory, since the law of conservation of angular momentum responsible for maintaining orientation in the SERF mode should not guarantee the preservation of alignment under the same conditions. A comparison with theoretically calculated parameters of SERF resonances in orientation is given. A qualitative explanation of the observed effect is presented.
We demonstrate a way of operating an optically pumped magnetometer with miniaturized cesium cell using the light-narrowing effect. The magnetometer setup shows improvement of shot-noise-limited sensitivity (42fT/Hz42\phantom{\rule{0.16em}{0ex}}\mathrm{fT}/\sqrt{\mathrm{Hz}}42fT/Hz​ in a cell of only 9.3mm39.3\phantom{\rule{0.16em}{0ex}}{\mathrm{mm}}^{3}9.3mm3 volume) due to the suppression of spin-exchange relaxation to a large extent and the use of a strikingly increased fraction of alkali-metal atoms for signal generation, working even in $\ensuremath{\mu}\mathrm{T}$ magnetic fields, by using only a single high-intensity laser beam both for pumping and probing of atomic spins.
Quantum manipulation technology and photoelectric detection technology have jointly facilitated the rapid development of ultra-sensitive atomic spin magnetometers. To improve the output signal and sensitivity of the spin-exchange-relaxation-free (SERF) atomic spin magnetometer, the noises influencing on the output signal and the sensitivity were analyzed, and the corresponding noise suppression methods were presented. The magnetic field noises, including the residual magnetic field noise and the light shift noise, were reduced to approximately zero by employing the magnetic field compensation method and by adjusting the frequency of the pump beam, respectively. With respect to the operation temperature, the simulation results showed that the temperature of the potassium atomic spin magnetometer realizing the spin-exchange relaxation-free regime was 180 °C. Moreover, the fluctuation noises of the frequency and the power were suppressed by using the frequency and the power stable systems. The experimental power stability results showed that the light intensity stability was enhanced 10%. Contrast experiments on the sensitivity were carried out to demonstrate the validity of the suppression methods. Finally, a sensitivity of 13 fT/Hz(1/2) was successfully achieved by suppressing noises and optimizing parameters.