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 A

Observation of Larmor spin precession of laser-cooled Rb atoms via paramagnetic Faraday rotation

T. Isayama, Yoshiro Takahashi, N. Tanaka, K. Toyoda, Kiyoshi Ishikawa, T. Yabuzaki

Published Jun 1, 1999• 37 citations
Publisher

Abstract

We have observed Larmor spin precession in the ground state of laser-cooled ${}^{85}\mathrm{Rb}$ atoms through paramagnetic Faraday rotation. We have been able to obtain a precision of $18\mathrm{pT}$ in the determination of the applied magnetic field, which proves the usefulness of laser-cooled atoms as an atomic magnetometer.

DOI
10.1103/physreva.59.4836

Related papers

Observation of spin echoes of laser-cooled Rb atoms

義朗 高橋, Yoshiro Takahashi, 和仁 本多 +7 more

We have observed gradient spin echoes in the ground state of laser-cooled 85Rb atoms through paramagnetic Faraday rotation. We have obtained the exact expression for the behavior of the echo signal under the assumption that the motion of the cold atoms is ballistic. The qualitative behaviors predicted by the theory have been confirmed experimentally. We demonstrate the usefulness of the spin echo method for the diagnosis for the atomic density distribution of cold atoms. We discuss various advantages of the spin echo as a novel method for temperature measurement.

•May 1, 1999•0 citations

Observation of spin echoes of laser-cooled Rb atoms

Yoshiro Takahashi, Takayuki Shimizu, N. Tanaka +3 more

We have observed gradient spin echoes in the ground state of $\mathrm{l}\mathrm{a}\mathrm{s}\mathrm{e}\mathrm{r}\ensuremath{-}\mathrm{c}\mathrm{o}\mathrm{o}\mathrm{l}\mathrm{e}\mathrm{d}{}^{85}\mathrm{Rb}$ atoms through paramagnetic Faraday rotation. We have obtained the exact expression for the behavior of the echo signal under the assumption that the motion of the cold atoms is ballistic. The qualitative behaviors predicted by the theory have been confirmed experimentally. We demonstrate the usefulness of the spin echo method for the diagnosis for the atomic density distribution of cold atoms. We discuss various advantages of the spin echo as a novel method for temperature measurement.

Physical Review A•May 1, 1999•4 citations

Optically induced spin precession and echo in an atomic beam

M. Zielonkowski, J. Steiger, U. Schünemann +2 more

We report on spin precession experiments using a ${}^{7}\mathrm{Li}$ atomic beam, which offers a perturbation-free environment to investigate spin dynamics under the influence of external fields. The ground-state magnetic moments perform a Larmor precession in a ``fictitious magnetic field'' induced by an off-resonant, circularly polarized laser beam. For a fictitious magnetic field parallel to a real one, we observe additional rotation of the spins, whereas an echo is observed if both fields are perpendicular with respect to each other. The systematics of these phenomena are studied.

Physical Review A•Nov 1, 1998•25 citations

Optical rotation in excess of 100 rad generated by Rb vapor in a multipass cell

Lun Li, Pranjal Vachaspati, D. Sheng +2 more

Paramagnetic Faraday rotation is a powerful technique for atom sensing widely used in quantum nondemolition measurements, fundamental symmetry tests, and other precision measurements. We demonstrate the use of a multipass optical cell for Faraday rotation spectroscopy and observe polarization rotation in excess of 100 rad from spin-polarized Rb vapor. Unlike optical cavities, multipass cells have a deterministic number of light passes and can be used to measure large optical rotations. We also observe a tenfold suppression of transverse spin relaxation when Rb atoms are placed in a coherent superposition state immune to spin-exchange collisions.

Physical Review A•Dec 6, 2011•83 citations

Probing the motion of cold atoms by Faraday spectroscopy

Greg Smith, Souma Chaudhury, Poul Jessen

We have implemented a continuous measurement of the mean magnetic moment of an ensemble of atoms trapped in a far-off-resonance optical lattice, by detecting the Faraday rotation of one of the lattice beams after it has passed through the atom cloud. In a first demonstration experiment we have observed Larmor precession with high signal-to-noise ratio, and compared the performance of the measurement with a simple theory. Faraday spectroscopy offers an ideal method to monitor the atomic dynamics and will be applied to the study of quantum chaos in magneto-optical lattices. In principle the measurement sensitivity can be increased to the point where quantum backaction becomes significant, thereby opening the door to studies of quantum feedback, spin squeezing and the role played by quantum measurement in quantum/classical correspondence.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 16, 2003•0 citations

Chopped nonlinear magneto-optic rotation: A technique for precision measurements

Harish Ravishankar, Sapam Ranjita Chanu, Vasant Natarajan A

We have developed a technique for precise measurement of small magnetic fields using nonlinear magneto-optic rotation (NMOR). The technique relies on the resonant laser beam being chopped. During the on time, the atoms are optically pumped into an aligned ground state (Delta m=2 coherence). During the off time, they freely precess around the magnetic field at the Larmor frequency. If the on-off modulation frequency matches (twice) the Larmor precession frequency, the rotation is resonantly enhanced in every cycle, thereby making the process like a repeated Ramsey measurement of the Larmor frequency. We study chopped-NMOR in a paraffin-coated Cs vapor cell. The out-of-phase demodulated rotation shows a Lorentzian peak of linewidth 85 mu G, corresponding to a sensitivity of 0.15nG/root Hz. We discuss the potential of this technique for the measurement of an atomic electric-dipole moment. Copyright (C) EPLA, 2011

•Jun 1, 2011•3 citations
We have observed Larmor spin precession in the ground state of laser-cooled 85Rb{}^{85}\mathrm{Rb}85Rb atoms through paramagnetic Faraday rotation. We have been able to obtain a precision of 18pT18\mathrm{pT}18pT in the determination of the applied magnetic field, which proves the usefulness of laser-cooled atoms as an atomic magnetometer.
We have observed gradient spin echoes in the ground state of laser-cooled 85Rb atoms through paramagnetic Faraday rotation. We have obtained the exact expression for the behavior of the echo signal under the assumption that the motion of the cold atoms is ballistic. The qualitative behaviors predicted by the theory have been confirmed experimentally. We demonstrate the usefulness of the spin echo method for the diagnosis for the atomic density distribution of cold atoms. We discuss various advantages of the spin echo as a novel method for temperature measurement.
We have observed gradient spin echoes in the ground state of $\mathrm{l}\mathrm{a}\mathrm{s}\mathrm{e}\mathrm{r}\ensuremath{-}\mathrm{c}\mathrm{o}\mathrm{o}\mathrm{l}\mathrm{e}\mathrm{d}{}^{85}\mathrm{Rb}$ atoms through paramagnetic Faraday rotation. We have obtained the exact expression for the behavior of the echo signal under the assumption that the motion of the cold atoms is ballistic. The qualitative behaviors predicted by the theory have been confirmed experimentally. We demonstrate the usefulness of the spin echo method for the diagnosis for the atomic density distribution of cold atoms. We discuss various advantages of the spin echo as a novel method for temperature measurement.
We report on spin precession experiments using a 7Li{}^{7}\mathrm{Li}7Li atomic beam, which offers a perturbation-free environment to investigate spin dynamics under the influence of external fields. The ground-state magnetic moments perform a Larmor precession in a ``fictitious magnetic field'' induced by an off-resonant, circularly polarized laser beam. For a fictitious magnetic field parallel to a real one, we observe additional rotation of the spins, whereas an echo is observed if both fields are perpendicular with respect to each other. The systematics of these phenomena are studied.
Paramagnetic Faraday rotation is a powerful technique for atom sensing widely used in quantum nondemolition measurements, fundamental symmetry tests, and other precision measurements. We demonstrate the use of a multipass optical cell for Faraday rotation spectroscopy and observe polarization rotation in excess of 100 rad from spin-polarized Rb vapor. Unlike optical cavities, multipass cells have a deterministic number of light passes and can be used to measure large optical rotations. We also observe a tenfold suppression of transverse spin relaxation when Rb atoms are placed in a coherent superposition state immune to spin-exchange collisions.
We have implemented a continuous measurement of the mean magnetic moment of an ensemble of atoms trapped in a far-off-resonance optical lattice, by detecting the Faraday rotation of one of the lattice beams after it has passed through the atom cloud. In a first demonstration experiment we have observed Larmor precession with high signal-to-noise ratio, and compared the performance of the measurement with a simple theory. Faraday spectroscopy offers an ideal method to monitor the atomic dynamics and will be applied to the study of quantum chaos in magneto-optical lattices. In principle the measurement sensitivity can be increased to the point where quantum backaction becomes significant, thereby opening the door to studies of quantum feedback, spin squeezing and the role played by quantum measurement in quantum/classical correspondence.
We have developed a technique for precise measurement of small magnetic fields using nonlinear magneto-optic rotation (NMOR). The technique relies on the resonant laser beam being chopped. During the on time, the atoms are optically pumped into an aligned ground state (Delta m=2 coherence). During the off time, they freely precess around the magnetic field at the Larmor frequency. If the on-off modulation frequency matches (twice) the Larmor precession frequency, the rotation is resonantly enhanced in every cycle, thereby making the process like a repeated Ramsey measurement of the Larmor frequency. We study chopped-NMOR in a paraffin-coated Cs vapor cell. The out-of-phase demodulated rotation shows a Lorentzian peak of linewidth 85 mu G, corresponding to a sensitivity of 0.15nG/root Hz. We discuss the potential of this technique for the measurement of an atomic electric-dipole moment. Copyright (C) EPLA, 2011