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

European Quantum Electronics Conference (EQEC)

One-dimensional raman cooling of cesium: towards the nanokelvin

Jakob Reichel, O. Morice, Guglielmo Maria Tino, Ch Salomon

Published Aug 24, 2005• 0 citations
Publisher

Abstract

In an all-diode-laser experiment, cesium atoms in a gas cell are trapped and pre-cooled to approx.5 μK in a magneto-optical trap followed by optical molasses. We were able to cool about 20% of the pre-cooled atoms into a narrow Gaussian velocity distribution with vrms = 1.9 mm/s = vrec/ 2. This corresponds to a one-dimensional temperature of 27 nK. Our Monte Carlo simulations indicate that velocities well below vrec should be attainable in this case as well in less than 40 ms.

DOI
10.1109/eqec.1994.698366

Related papers

Subrecoil Raman Cooling of Cesium Atoms

Jakob Reichel, O. Morice, Guglielmo Maria Tino +1 more

We use velocity-selective Raman pulses generated by two diode lasers to cool cesium atoms in 1 dimension to an r.m.s. of 1.2 mm/s. This is about 1/3 of the single-photon recoil velocity v rec = ℏk/M , where ℏk is the photon momentum and M the atom's mass. The corresponding effective temperature is a factor of 9 below the single-photon recoil temperature given by k B T rec /2 = 1/2 Mv rec 2 . Because of the high cesium mass, this temperature is only (23 ± 5) nanokelvin, the lowest 1D kinetic temperature reported to date.

Europhysics Letters (EPL)•Dec 1, 1994•33 citations

Laser Cooling of Cesium Atoms Below 3 μK

Ch Salomon, Jean Dalibard, William D. Phillips +2 more

We have measured the temperature of cesium atoms released from optical molasses. For a wide range of laser intensity and detuning from resonance, the temperature depends only on the intensity-to-detuning ratio. The lowest temperature achieved is (2.5 ± 0.6) μK, which corresponds to an r.m.s. velocity of 12.5 mm/s or 3.6 times the single-photon recoil velocity. This is, to our knowledge, the coldest kinetic temperature ever measured for three-dimensional (3D) cooling.

Europhysics Letters (EPL)•Aug 15, 1990•239 citations

Beyond Optical Molasses: 3D Raman Sideband Cooling of Atomic Cesium to High Phase-Space Density

Andrew J. Kerman, Vladan Vuletić, Cheng Chin +1 more

We demonstrate a simple, general purpose method to cool neutral atoms. A sample containing $3\ifmmode\times\else\texttimes\fi{}{10}^{8}$ cesium atoms prepared in a magneto-optical trap is cooled and simultaneously spin polarized in 10 ms at a density of $1.1\ifmmode\times\else\texttimes\fi{}{10}^{11}\mathrm{cm}{}^{\ensuremath{-}3}$ to a phase space density $n{\ensuremath{\lambda}}_{\mathrm{dB}}^{3}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1/500$, which is almost 3 orders of magnitude higher than attainable in free space with optical molasses. The technique is based on 3D degenerate Raman sideband cooling in optical lattices and remains efficient even at densities where the mean lattice site occupation is close to unity.

Physical Review Letters•Jan 17, 2000•264 citations

Sub-Doppler laser cooling of fermionic 40K atoms

Giovanni Carlo Modugno, Craig Benko, Peter Hannaford +2 more

We report laser cooling of fermionic ${}^{40}\mathrm{K}$ atoms, with temperatures down to $(15\ifmmode\pm\else\textpm\fi{}5) \ensuremath{\mu}\mathrm{K},$ for an enriched sample trapped in a magneto-optical trap and additionaly cooled in optical molasses. This temperature is a factor of 10 below the Doppler-cooling limit and corresponds to an rms velocity within a factor of 2 of the lowest realizable rms velocity $(\ensuremath{\sim}{3.5v}_{\mathrm{rec}})$ in three-dimensional optical molasses. Realization of such low atom temperatures, up to now only accessible with evaporative cooling techniques, is an important precursor to producing a degenerate Fermi gas of ${}^{40}\mathrm{K}$ atoms.

arXiv:cond-mat/9908102•Physical Review A•Nov 1, 1999•32 citations

Laser cooling of cesium atoms below 3 microkelvins

Christophe Salomon, Jean Dalibard, William D. Phillips +2 more

We have measured the temperature of cesium atoms released from optical molasses. For a wide range of laser intensity and detuning from resonance, the temperature depends only on the intensity to detuning ratio. The lowest temperature achieved is 2.5±0.6 μK, which corresponds to an rms velocity of 12.5 mm/s or 3.6 times the single‐photon recoil velocity. This is, to our knowledge, the coldest kinetic temperature ever measured for three dimensional (3D) cooling. We then discuss the possibility of using such a cold sample of atoms for realizing a high performance atomic clock in a fountain geometry. In particular, a method for launching the atoms upwards, while maintaining the very cold temperature, is demonstrated.

AIP conference proceedings•Jan 1, 1991•5 citations

Three-dimensional cooling of cesium atoms in four-beam gray optical molasses

Denis Boiron, C. Triché, D. R. Meacher +2 more

We report the observation of three-dimensional cooling of cesium atoms using a four-beam optical molasses tuned to the blue side of the ${\mathit{F}}_{\mathit{g}}$=3\ensuremath{\rightarrow}${\mathit{F}}_{\mathit{e}}$=2 hyperfine component of the 6${\mathit{S}}_{1/2}$\ensuremath{\rightarrow}6${\mathit{P}}_{3/2}$ transition. The cooling mechanism is a Sisyphus effect involving atomic states that are nearly uncoupled from the light field. Starting from a magneto-optical trap at 70 \ensuremath{\mu}K, the cooling time was on the order of 1 ms with almost 100% capture efficiency and temperature smaller than 5 \ensuremath{\mu}K measured. We also present a probe transmission spectrum showing that almost all the atoms are found in the nearly dark states.

Physical Review A•Nov 1, 1995•68 citations
In an all-diode-laser experiment, cesium atoms in a gas cell are trapped and pre-cooled to approx.5 μK in a magneto-optical trap followed by optical molasses. We were able to cool about 20% of the pre-cooled atoms into a narrow Gaussian velocity distribution with vrms = 1.9 mm/s = vrec/ 2. This corresponds to a one-dimensional temperature of 27 nK. Our Monte Carlo simulations indicate that velocities well below vrec should be attainable in this case as well in less than 40 ms.
We use velocity-selective Raman pulses generated by two diode lasers to cool cesium atoms in 1 dimension to an r.m.s. of 1.2 mm/s. This is about 1/3 of the single-photon recoil velocity v rec = ℏk/M , where ℏk is the photon momentum and M the atom's mass. The corresponding effective temperature is a factor of 9 below the single-photon recoil temperature given by k B T rec /2 = 1/2 Mv rec 2 . Because of the high cesium mass, this temperature is only (23 ± 5) nanokelvin, the lowest 1D kinetic temperature reported to date.
We demonstrate a simple, general purpose method to cool neutral atoms. A sample containing $3\ifmmode\times\else\texttimes\fi{}{10}^{8}$ cesium atoms prepared in a magneto-optical trap is cooled and simultaneously spin polarized in 10 ms at a density of $1.1\ifmmode\times\else\texttimes\fi{}{10}^{11}\mathrm{cm}{}^{\ensuremath{-}3}$ to a phase space density $n{\ensuremath{\lambda}}_{\mathrm{dB}}^{3}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1/500$, which is almost 3 orders of magnitude higher than attainable in free space with optical molasses. The technique is based on 3D degenerate Raman sideband cooling in optical lattices and remains efficient even at densities where the mean lattice site occupation is close to unity.
We report laser cooling of fermionic 40K{}^{40}\mathrm{K}40K atoms, with temperatures down to $(15\ifmmode\pm\else\textpm\fi{}5) \ensuremath{\mu}\mathrm{K},$ for an enriched sample trapped in a magneto-optical trap and additionaly cooled in optical molasses. This temperature is a factor of 10 below the Doppler-cooling limit and corresponds to an rms velocity within a factor of 2 of the lowest realizable rms velocity $(\ensuremath{\sim}{3.5v}_{\mathrm{rec}})$ in three-dimensional optical molasses. Realization of such low atom temperatures, up to now only accessible with evaporative cooling techniques, is an important precursor to producing a degenerate Fermi gas of 40K{}^{40}\mathrm{K}40K atoms.
We have measured the temperature of cesium atoms released from optical molasses. For a wide range of laser intensity and detuning from resonance, the temperature depends only on the intensity to detuning ratio. The lowest temperature achieved is 2.5±0.6 μK, which corresponds to an rms velocity of 12.5 mm/s or 3.6 times the single‐photon recoil velocity. This is, to our knowledge, the coldest kinetic temperature ever measured for three dimensional (3D) cooling. We then discuss the possibility of using such a cold sample of atoms for realizing a high performance atomic clock in a fountain geometry. In particular, a method for launching the atoms upwards, while maintaining the very cold temperature, is demonstrated.
We report the observation of three-dimensional cooling of cesium atoms using a four-beam optical molasses tuned to the blue side of the Fg{\mathit{F}}_{\mathit{g}}Fg​=3\ensuremath{\rightarrow}Fe{\mathit{F}}_{\mathit{e}}Fe​=2 hyperfine component of the 6S1/2{\mathit{S}}_{1/2}S1/2​\ensuremath{\rightarrow}6P3/2{\mathit{P}}_{3/2}P3/2​ transition. The cooling mechanism is a Sisyphus effect involving atomic states that are nearly uncoupled from the light field. Starting from a magneto-optical trap at 70 \ensuremath{\mu}K, the cooling time was on the order of 1 ms with almost 100% capture efficiency and temperature smaller than 5 \ensuremath{\mu}K measured. We also present a probe transmission spectrum showing that almost all the atoms are found in the nearly dark states.