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

IEEE Transactions on Instrumentation and Measurement

Cooling in an Optical Lattice for a Caesium Fountain Frequency Standard

Witold Chałupczak, K. Szymaniec, D. Henderson

Published Mar 21, 2005• 4 citations
Publisher

Abstract

We report progress toward a Cs-fountain frequency standard operating in the nanokelvin temperature range. We have implemented the Raman sideband cooling in a far-off-resonance optical lattice and observed subrecoil temperatures of 200 nK. We have studied the structure of the lattice and optimized the capture of atoms released from the magneto-optical trap into the lattice. In addition, the atoms, accumulated by the cooling scheme in the stretched magnetic state m/sub F/=3, have been transferred to the magnetically insensitive state m/sub F/=0 by using the adiabatic-passage technique.

DOI
10.1109/tim.2005.843572

Related papers

Two-dimensional sideband Raman cooling and m=0 Zeeman state preparation in an optical lattice

А. В. Тайченачев, Anatolii M Tumaikin, Valeriy I. Yudin +1 more

Summary form only given. Laser cooled atoms play a critical role in modern designs of frequency standards such as atomic fountains. Recently, an elegant and efficient method of two-dimensional cooling to the vibrational ground state of a far-off resonance optical lattice has been demonstrated. This method is a variant of Raman sideband cooling based on the Raman transitions between the vibrational manifolds of adjacent Zeeman substates. A static magnetic field is used to tune the Zeeman levels so that Raman resonance occurs on the red sideband and results in cooling. Two circularly polarized fields are used to recycle the atoms for repetitive Raman cooling. Unfortunately, a direct application of this scheme to frequency standards meets with several difficulties. Stimulated by these concepts and results, we propose a new variant of transverse sideband cooling, where these problems are avoided, while still maintaining most of the attractive features. The field configuration used for the optical lattice consists of three linearly polarized beams having equal amplitudes and propagating in the xy plane with angles of 2/spl pi//3 between each other. The polarization vectors of these beams are tilted through a small angle with respect to the z-axis. All the beams have the same frequency far-detuned to the red of the D/sub 2/ resonance line. Raman transitions between vibrational levels of adjacent magnetic substates are induced by the small in-plane component of the field. Two other important requirements for Raman sideband cooling are a uniform energy shift of the magnetic sublevels and optical pumping.

Quantum Electronics and Laser Science Conference•May 12, 2000•0 citations

Resolved-Sideband Raman Cooling to the Ground State of an Optical Lattice

S. E. Hamann, D. L. Haycock, Gerd Klose +3 more

We trap neutral Cs atoms in a two-dimensional optical lattice and cool them close to the zero point of motion by resolved-sideband Raman cooling. Sideband cooling occurs via transitions between the vibrational manifolds associated with a pair of magnetic sublevels, and the required Raman coupling is provided by the lattice potential itself. We obtain mean vibrational excitations ${\overline{n}}_{x}\ensuremath{\approx}{\overline{n}}_{y}<0.024$, corresponding to a population $>95%$ in the vibrational ground state. Atoms in the ground state of an optical lattice provide a new system in which to explore quantum state control and subrecoil laser cooling.

arXiv:quant-ph/9801025•Physical Review Letters•May 11, 1998•245 citations

High-brightness atom source for atomic fountains

Philipp Treutlein, Keng Yeow Chung, Steven Chu

We launch Cs atoms using a moving three-dimensional (3D) optical lattice. Atoms are initially spin polarized and cooled to the ground state of the optical potential using 3D Raman sideband cooling and then accelerated in the lattice to velocities of up to $3 \mathrm{m}/\mathrm{s}.$ Subsequent adiabatic lowering of the potential releases the atoms from the lattice. Three-dimensional kinetic temperatures as low as $200 \mathrm{nK}$ were achieved. The observed temperature of the launch is independent of the acceleration and final velocity of the atoms. In an alternative approach, we first accelerate the atoms to velocities of up to 5 m/s using moving molasses and then cool them with the lattice in the comoving frame of the atoms to temperatures as low as 150 nK.

Physical Review A•Apr 9, 2001•82 citations

Adiabatic passage in an open multilevel system

Witold Chałupczak, K. Szymaniec

The preparation of a sample of ultra cold caesium atoms in an ${m}_{F}=0$ Zeeman sublevel of the $F=3$ ground state is demonstrated, using cooling in an optical lattice and adiabatic passage. 97% of the atoms finally detected in the experiment populate the ${m}_{F}=0$ sublevel at a temperature of $300\phantom{\rule{0.3em}{0ex}}\mathrm{nK}$. Microwave spectroscopy is used to measure the adiabatic transfer directly and its dependence on various experimental parameters. A theoretical model is provided to estimate the upper limit for the efficiency of adiabatic transfer in a multilevel system with nonresonant excitation. The results constitute significant progress towards constructing a caesium fountain frequency standard operating in the nK temperature range.

Physical Review A•May 27, 2005•10 citations

Enhanced Raman sideband cooling of caesium atoms in a vapour-loaded magneto-optical trap

Y. Li, Jizhou Wu, G Feng +6 more

We report enhanced three-dimensional degenerated Raman sideband cooling (3D DRSC) of caesium (Cs) atoms in a standard single-cell vapour-loaded magneto-optical trap. Our improved scheme involves using a separate repumping laser and optimized lattice detuning. We load 1.5 × 10 7 atoms into the Raman lattice with a detuning of −15.5 GHz (to the ground F = 3 state). Enhanced 3D DRSC is used to cool them from 60 µ K to 1.7 µ K within 12 ms and the number of obtained atoms is about 1.2 × 10 7 . A theoretical model is proposed to simulate the measured number of trapped atoms. The result shows good agreement with the experimental data. The technique paves the way for loading a large number of ultracold Cs atoms into a crossed dipole trap and efficient evaporative cooling in a single-cell system.

arXiv:1503.05952•Laser Physics Letters•Mar 31, 2015•9 citations

Atom-trapping in the Lamb-Dicke regime in a far-off-resonance optical lattice

D. L. Haycock, S. E. Hamann, Gerd Klose +1 more

We form a 1D optical lattices for Cs atoms using light tuned a few thousand linewidths below the 6S1/2(F equals 4) yields 6P3/2(F' equals 5) transition at 852 nm. In this far-off- resonance lattice the time scale for damping of motional coherences and kinetic energy can be orders of magnitude longer than the vibrational oscillation period for atoms trapped in the lattice potential wells. Atoms are loaded directly into deeply bound states, by adiabatic transfer from a superimposed, near-resonance optical lattice. This yields a mean vibrational excitation n approximately equals 0.3, and localization (Delta) z approximately (lambda) /20 deep in the Lamb-Dicke regime. Light scattering subsequently heats the atoms, but the initial rate is only of order 10-3 vibrational quanta per oscillation period. Low vibrational excitation, localization in the Lamb-Dicke regime and low heating rates make these atoms good candidates for resolved- sideband Raman cooling, and for the generation and study of non-classical states of center-of-mass motion. We propose a scheme for resolved-sideband Raman cooling and quantum state preparation; the scheme employs Raman coupling between magnetic sublevels induced by the lattice light field itself.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 1, 1997•1 citation
We report progress toward a Cs-fountain frequency standard operating in the nanokelvin temperature range. We have implemented the Raman sideband cooling in a far-off-resonance optical lattice and observed subrecoil temperatures of 200 nK. We have studied the structure of the lattice and optimized the capture of atoms released from the magneto-optical trap into the lattice. In addition, the atoms, accumulated by the cooling scheme in the stretched magnetic state m/sub F/=3, have been transferred to the magnetically insensitive state m/sub F/=0 by using the adiabatic-passage technique.
Summary form only given. Laser cooled atoms play a critical role in modern designs of frequency standards such as atomic fountains. Recently, an elegant and efficient method of two-dimensional cooling to the vibrational ground state of a far-off resonance optical lattice has been demonstrated. This method is a variant of Raman sideband cooling based on the Raman transitions between the vibrational manifolds of adjacent Zeeman substates. A static magnetic field is used to tune the Zeeman levels so that Raman resonance occurs on the red sideband and results in cooling. Two circularly polarized fields are used to recycle the atoms for repetitive Raman cooling. Unfortunately, a direct application of this scheme to frequency standards meets with several difficulties. Stimulated by these concepts and results, we propose a new variant of transverse sideband cooling, where these problems are avoided, while still maintaining most of the attractive features. The field configuration used for the optical lattice consists of three linearly polarized beams having equal amplitudes and propagating in the xy plane with angles of 2/spl pi//3 between each other. The polarization vectors of these beams are tilted through a small angle with respect to the z-axis. All the beams have the same frequency far-detuned to the red of the D/sub 2/ resonance line. Raman transitions between vibrational levels of adjacent magnetic substates are induced by the small in-plane component of the field. Two other important requirements for Raman sideband cooling are a uniform energy shift of the magnetic sublevels and optical pumping.
We trap neutral Cs atoms in a two-dimensional optical lattice and cool them close to the zero point of motion by resolved-sideband Raman cooling. Sideband cooling occurs via transitions between the vibrational manifolds associated with a pair of magnetic sublevels, and the required Raman coupling is provided by the lattice potential itself. We obtain mean vibrational excitations ${\overline{n}}_{x}\ensuremath{\approx}{\overline{n}}_{y}<0.024$, corresponding to a population >95>95%>95 in the vibrational ground state. Atoms in the ground state of an optical lattice provide a new system in which to explore quantum state control and subrecoil laser cooling.
We launch Cs atoms using a moving three-dimensional (3D) optical lattice. Atoms are initially spin polarized and cooled to the ground state of the optical potential using 3D Raman sideband cooling and then accelerated in the lattice to velocities of up to 3m/s.3 \mathrm{m}/\mathrm{s}.3m/s. Subsequent adiabatic lowering of the potential releases the atoms from the lattice. Three-dimensional kinetic temperatures as low as 200nK200 \mathrm{nK}200nK were achieved. The observed temperature of the launch is independent of the acceleration and final velocity of the atoms. In an alternative approach, we first accelerate the atoms to velocities of up to 5 m/s using moving molasses and then cool them with the lattice in the comoving frame of the atoms to temperatures as low as 150 nK.
The preparation of a sample of ultra cold caesium atoms in an mF=0{m}_{F}=0mF​=0 Zeeman sublevel of the F=3F=3F=3 ground state is demonstrated, using cooling in an optical lattice and adiabatic passage. 97% of the atoms finally detected in the experiment populate the mF=0{m}_{F}=0mF​=0 sublevel at a temperature of 300nK300\phantom{\rule{0.3em}{0ex}}\mathrm{nK}300nK. Microwave spectroscopy is used to measure the adiabatic transfer directly and its dependence on various experimental parameters. A theoretical model is provided to estimate the upper limit for the efficiency of adiabatic transfer in a multilevel system with nonresonant excitation. The results constitute significant progress towards constructing a caesium fountain frequency standard operating in the nK temperature range.
We report enhanced three-dimensional degenerated Raman sideband cooling (3D DRSC) of caesium (Cs) atoms in a standard single-cell vapour-loaded magneto-optical trap. Our improved scheme involves using a separate repumping laser and optimized lattice detuning. We load 1.5 × 10 7 atoms into the Raman lattice with a detuning of −15.5 GHz (to the ground F = 3 state). Enhanced 3D DRSC is used to cool them from 60 µ K to 1.7 µ K within 12 ms and the number of obtained atoms is about 1.2 × 10 7 . A theoretical model is proposed to simulate the measured number of trapped atoms. The result shows good agreement with the experimental data. The technique paves the way for loading a large number of ultracold Cs atoms into a crossed dipole trap and efficient evaporative cooling in a single-cell system.
We form a 1D optical lattices for Cs atoms using light tuned a few thousand linewidths below the 6S1/2(F equals 4) yields 6P3/2(F' equals 5) transition at 852 nm. In this far-off- resonance lattice the time scale for damping of motional coherences and kinetic energy can be orders of magnitude longer than the vibrational oscillation period for atoms trapped in the lattice potential wells. Atoms are loaded directly into deeply bound states, by adiabatic transfer from a superimposed, near-resonance optical lattice. This yields a mean vibrational excitation n approximately equals 0.3, and localization (Delta) z approximately (lambda) /20 deep in the Lamb-Dicke regime. Light scattering subsequently heats the atoms, but the initial rate is only of order 10-3 vibrational quanta per oscillation period. Low vibrational excitation, localization in the Lamb-Dicke regime and low heating rates make these atoms good candidates for resolved- sideband Raman cooling, and for the generation and study of non-classical states of center-of-mass motion. We propose a scheme for resolved-sideband Raman cooling and quantum state preparation; the scheme employs Raman coupling between magnetic sublevels induced by the lattice light field itself.