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

Chinese Physics Letters

Ultra-Slow Atomic Beam Generation by Velocity Selective Resonance

Hongyu Ma, Cheng Hua-Dong, Wang Yu-Zhu, Liang Liu, Harold J. Metcalf

Published May 1, 2008• 1 citation
Publisher

Abstract

We describe a method to generate an ultra-slow atomic beam by velocity selective resonance (VSR). A VSR experiment on a metastable helium beam in a magnetic field is presented and the results show that the transverse velocity of the deflected beam can be cooled and precisely controlled to less than the recoil velocity, depending on the magnitude of the magnetic field. We extend this idea to a cold atomic cloud to produce an ultra slow 87 Rb beam that can be used as a source of an atomic fountain clock or a space clock.

DOI
10.1088/0256-307x/25/5/034

Related papers

Generation of a slow and continuous cesium atomic beam for an atomic clock

Sang Eon Park, Ho Seong Lee, Eun-joo Shin +3 more

A thermal atomic beam from a cesium oven was slowed down by use of the Hoffnagle modified white-light cooling technique. In addition, the atomic beam was collimated by use of a two-dimensional optical molasses that was installed transverse to the atomic-beam direction. The flux of the atomic beam was 2×1010 atoms/s, an increase of a factor of 16 as a result of the collimation. The mean longitudinal velocity was ∼24.4 m/s, and the rms velocity spread of the slowed atomic beam was ∼1 m/s. Compared with other methods, we found that the Hoffnagle method is suitable for the generation of slow atomic beams to be used in an atomic clock, which requires an ultralow magnetic field environment. This atomic beam was deflected by an angle of 30° by a one-dimensional optical molasses to separate it from laser light and high-velocity atoms.

Journal of the Optical Society of America B•Nov 1, 2002•21 citations

Pulsed magnetic slowing of supersonic beams

Christian G. Parthey

Supersonic beams provide a source of cold atoms where laser cooling is not applicable. Although the atoms' temperature in the co-moving frame is in the subkelvin range their velocity is on the order of several hundreds of meters per second. This thesis describes the experimental realization of a novel method to slow atoms and molecules with permanent magnetic moments using pulsed magnetic fields. The method is suitable for most elements since most atomic species are paramagnetic, and can also be applied to certain molecules, as well as electronically excited metastable states and most radicals. We show the slowing of metastable neon in a proof of principle experiment where the mean velocity is reduced from 461.0[plus or minus] 7.7 m/s to 403 [plus or minus]16 m/s in 18 stages. A second setup with 64 stages is now operating and allows us to stop metastable neon in principle. Preliminary results showing slowing from 447[plus or minus]3m/s to 136[plus or minus]5m/s with an efficiency of up to 3.9% are included here, and the slower has been shown to generate atoms as slow as 50 m/s. We find that the slowing efficiency depends strongly on the switching phase. In addition to the experimental results described above, we present simulations of a moving trap which allows trapping and decelerating at the same time.

•Jan 1, 2017•0 citations

Velocity-selective magnetic-resonance laser cooling

S-Q. Shang, B. Sheehy, P. van der Straten +1 more

We describe a new sub-Doppler cooling scheme that cools atoms to nonzero velocity ${\mathit{v}}_{\mathit{r}}$. The atomic motion in a combined optical standing wave and constant magnetic field induces a velocity-selective magnetic resonance that produces strong cooling for negative laser detuning to ${\mathit{v}}_{\mathit{r}}$=${\mathrm{\ensuremath{\omega}}}_{\mathit{Z}}$/2k, with ${\mathrm{\ensuremath{\omega}}}_{\mathit{Z}}$ the Larmor frequency. In a one-dimensinal optical molasses transverse to a thermal Rb beam we observe the bunching of the atoms into two peaks corresponding to \ifmmode\pm\else\textpm\fi{}${\mathit{v}}_{\mathit{r}}$. We present a quantitative comparison between our theory and experiment and suggest some applications.

Physical Review Letters•Jul 16, 1990•51 citations

High-brilliance Zeeman-slowed cesium atomic beam

Frank Lison, P. Schuh, D. Haubrich +1 more

We have built a Zeeman-slower apparatus which produces a slow and cold cesium atomic beam. The atomic beam has a mean velocity in the range 35--120 m/s and a high atomic current of more than $2\ifmmode\times\else\texttimes\fi{}{10}^{10}$ cold atoms/s. A small longitudinal velocity spread was achieved by optimizing the termination of the slowing process. The measured value of less than 1 m/s is consistent with a numerical simulation of the slowing process. With a magnetic lens and a tilted two-dimensional optical molasses stage, the slow atomic beam is transversely compressed, collimated, and deflected. We achieve a transverse temperature below the Doppler limit. The brilliance of this beam has been determined to be $7\ifmmode\times\else\texttimes\fi{}{10}^{23}$ atoms ${\mathrm{s}}^{\ensuremath{-}1}{\mathrm{m}}^{\ensuremath{-}2}$ ${\mathrm{sr}}^{\ensuremath{-}1}.$ By optical pumping the slow atomic beam can be polarized in the outermost magnetic substates ${F=4,m}_{F}=\ifmmode\pm\else\textpm\fi{}4,$ of the cesium ground state. This brilliant beam is an ideal source for experiments in atom optics and atom lithography.

Physical Review A•Dec 10, 1999•52 citations

Velocity-selective resonances and sub-Doppler laser cooling

S-Q. Shang, B. Sheehy, H. Metcalf +2 more

We describe several one-dimensional sub-Doppler laser-cooling experiments that cool Rb to finite and zero velocities in a magnetic field and polarization gradients. We then present a physical picture that unifies these measurements in terms of coherent two-photon velocity-selective resonances between atomic ground-state sublevels (including Raman resonances). We propose several sub-Doppler cooling schemes without fields or without polarization gradients, based on VSR between nondegenerate ground states.

Physical Review Letters•Aug 26, 1991•57 citations

Ultra-Narrow Velocity Distributions of Slow Atoms Produced with the Zeeman Tuning Technique

Sérgio Carlos Zílio, Vanderlei Salvador Bagnato

We report on the use of a stimulated Raman transition in a slowed atomic beam to produce a narrow velocity distribution of atoms in a selected electronic state, which could be used for atomic collisions studies in the low temperature regime(1). The velocity selection is part of the deceleration process and in this sense it is unique. The atomic beam is decelerated by the radiation pressure force exerted on the atoms by a counter- propagating laser beam. The resonance condition is maintained along the deceleration path because the changing Doppler shift is compensated by Zeeman tuning the electronic sublevels(2) with a spatialy inhomogneous magnetic field. At the end of the slowing process, the initial Maxwell-Boltzman distribution is compressed to a narrow velocity distribution (Δv ~ 50 m/s), centered close to v = 0. This velocity bunching(3) increases considerably the number of atoms in each velocity class, allowing the use of velocity selection techniques as a feasible way of studying low velocity collisions.

High Resolution Spectroscopy•Jan 1, 1993•0 citations
We describe a method to generate an ultra-slow atomic beam by velocity selective resonance (VSR). A VSR experiment on a metastable helium beam in a magnetic field is presented and the results show that the transverse velocity of the deflected beam can be cooled and precisely controlled to less than the recoil velocity, depending on the magnitude of the magnetic field. We extend this idea to a cold atomic cloud to produce an ultra slow 87 Rb beam that can be used as a source of an atomic fountain clock or a space clock.
A thermal atomic beam from a cesium oven was slowed down by use of the Hoffnagle modified white-light cooling technique. In addition, the atomic beam was collimated by use of a two-dimensional optical molasses that was installed transverse to the atomic-beam direction. The flux of the atomic beam was 2×1010 atoms/s, an increase of a factor of 16 as a result of the collimation. The mean longitudinal velocity was ∼24.4 m/s, and the rms velocity spread of the slowed atomic beam was ∼1 m/s. Compared with other methods, we found that the Hoffnagle method is suitable for the generation of slow atomic beams to be used in an atomic clock, which requires an ultralow magnetic field environment. This atomic beam was deflected by an angle of 30° by a one-dimensional optical molasses to separate it from laser light and high-velocity atoms.
Supersonic beams provide a source of cold atoms where laser cooling is not applicable. Although the atoms' temperature in the co-moving frame is in the subkelvin range their velocity is on the order of several hundreds of meters per second. This thesis describes the experimental realization of a novel method to slow atoms and molecules with permanent magnetic moments using pulsed magnetic fields. The method is suitable for most elements since most atomic species are paramagnetic, and can also be applied to certain molecules, as well as electronically excited metastable states and most radicals. We show the slowing of metastable neon in a proof of principle experiment where the mean velocity is reduced from 461.0[plus or minus] 7.7 m/s to 403 [plus or minus]16 m/s in 18 stages. A second setup with 64 stages is now operating and allows us to stop metastable neon in principle. Preliminary results showing slowing from 447[plus or minus]3m/s to 136[plus or minus]5m/s with an efficiency of up to 3.9% are included here, and the slower has been shown to generate atoms as slow as 50 m/s. We find that the slowing efficiency depends strongly on the switching phase. In addition to the experimental results described above, we present simulations of a moving trap which allows trapping and decelerating at the same time.
We describe a new sub-Doppler cooling scheme that cools atoms to nonzero velocity vr{\mathit{v}}_{\mathit{r}}vr​. The atomic motion in a combined optical standing wave and constant magnetic field induces a velocity-selective magnetic resonance that produces strong cooling for negative laser detuning to vr{\mathit{v}}_{\mathit{r}}vr​=${\mathrm{\ensuremath{\omega}}}_{\mathit{Z}}$/2k, with ${\mathrm{\ensuremath{\omega}}}_{\mathit{Z}}$ the Larmor frequency. In a one-dimensinal optical molasses transverse to a thermal Rb beam we observe the bunching of the atoms into two peaks corresponding to \ifmmode\pm\else\textpm\fi{}vr{\mathit{v}}_{\mathit{r}}vr​. We present a quantitative comparison between our theory and experiment and suggest some applications.
We have built a Zeeman-slower apparatus which produces a slow and cold cesium atomic beam. The atomic beam has a mean velocity in the range 35--120 m/s and a high atomic current of more than $2\ifmmode\times\else\texttimes\fi{}{10}^{10}$ cold atoms/s. A small longitudinal velocity spread was achieved by optimizing the termination of the slowing process. The measured value of less than 1 m/s is consistent with a numerical simulation of the slowing process. With a magnetic lens and a tilted two-dimensional optical molasses stage, the slow atomic beam is transversely compressed, collimated, and deflected. We achieve a transverse temperature below the Doppler limit. The brilliance of this beam has been determined to be $7\ifmmode\times\else\texttimes\fi{}{10}^{23}$ atoms ${\mathrm{s}}^{\ensuremath{-}1}{\mathrm{m}}^{\ensuremath{-}2}$ ${\mathrm{sr}}^{\ensuremath{-}1}.$ By optical pumping the slow atomic beam can be polarized in the outermost magnetic substates ${F=4,m}_{F}=\ifmmode\pm\else\textpm\fi{}4,$ of the cesium ground state. This brilliant beam is an ideal source for experiments in atom optics and atom lithography.
We describe several one-dimensional sub-Doppler laser-cooling experiments that cool Rb to finite and zero velocities in a magnetic field and polarization gradients. We then present a physical picture that unifies these measurements in terms of coherent two-photon velocity-selective resonances between atomic ground-state sublevels (including Raman resonances). We propose several sub-Doppler cooling schemes without fields or without polarization gradients, based on VSR between nondegenerate ground states.
We report on the use of a stimulated Raman transition in a slowed atomic beam to produce a narrow velocity distribution of atoms in a selected electronic state, which could be used for atomic collisions studies in the low temperature regime(1). The velocity selection is part of the deceleration process and in this sense it is unique. The atomic beam is decelerated by the radiation pressure force exerted on the atoms by a counter- propagating laser beam. The resonance condition is maintained along the deceleration path because the changing Doppler shift is compensated by Zeeman tuning the electronic sublevels(2) with a spatialy inhomogneous magnetic field. At the end of the slowing process, the initial Maxwell-Boltzman distribution is compressed to a narrow velocity distribution (Δv ~ 50 m/s), centered close to v = 0. This velocity bunching(3) increases considerably the number of atoms in each velocity class, allowing the use of velocity selection techniques as a feasible way of studying low velocity collisions.