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 Letters

Magneto-Optical Trapping and Cooling of Strontium Atoms down to the Photon Recoil Temperature

Hidetoshi Katori, T. Ido, Yoshitomo Isoya, Makoto Kuwata‐Gonokami

Published Feb 8, 1999• 376 citations
Publisher

Abstract

We report narrow-line laser cooling and trapping of strontium atoms down to the photon recoil temperature. ${}^{88}\mathrm{Sr}$ atoms precooled by the broad $^{1}S_{0}\ensuremath{-}^{1}P_{1}$ transition at 461 nm were further cooled in a magneto-optical trap using the spin-forbidden transition $^{1}S_{0}\ensuremath{-}^{3}P_{1}$ at 689 nm. We have thus obtained an atomic sample with a density over ${10}^{12}\mathrm{cm}{}^{\ensuremath{-}3}$ and a minimum temperature of 400 nK, corresponding to a maximum phase space density of ${10}^{\ensuremath{-}2}$ which is 3 orders of magnitude larger than the value that has been obtained by magneto-optical traps to date. This scheme provides us an opportunity and system to study quantum statistical properties of degenerate fermions as well as bosons.

DOI
10.1103/physrevlett.82.1116

Related papers

Laser cooling of strontium atoms towards the quantum degenerate regime

Hidetoshi Katori, T. Ido, Yoshitomo Isoya +1 more

Summary form only given. All-optical production of quantum degenerate atomic gases has been one of the long-standing targets in laser cooling. We report a novel approach towards this direction based on a narrow-line laser cooling for strontium atoms. By employing two transitions with markedly different dipole moments, i.e., the allowed /sup 1/S/sub 0/-/sup 1/P/sub 1/ (/spl lambda/=461 nm, /spl gamma/=2/spl pi//spl times/32 MHz) and the spin-forbidden /sup 1/S/sub 0/-/sup 3/P/sub 1/ (/spl lambda/=689 nm, /spl gamma/=2/spl pi//spl times/7.6 kHz) transition, thermal strontium atoms were Doppler-cooled down to 400 nK or the photon recoil temperature, in a magneto-optical trap (MOT). Presents the corresponding energy levels for cooling and trapping. The use of a narrow spin-forbidden transition successfully reduced the radiation trapping effects at a high atom density over 10/sup 12//cm/sup 3/, thus enabling us to attain the hitherto high phase space density of 0.01 in a MOT.

Conference on Lasers and Electro-Optics•Aug 29, 2005•2 citations

Laser cooling of strontium atoms toward quantum degeneracy

Hidetoshi Katori

We report on a narrow-line laser cooling and trapping of strontium atoms near quantum degeneracy. Employing a magneto-optical trap (MOT) on the spin-forbidden transition 1S0−3P1 at 689 nm, we have laser-cooled an atomic sample down to the photon recoil temperature of 400 nK with a phase space density of 10−2. The atoms were then compressed into a new type of far-off resonance optical dipole trap that was designed to allow simultaneous Doppler cooling, resulting in a phase space density of 10% to that required for quantum degeneracy. It is shown that this value is finally limited by light-assisted collisions occurring in the optical cooling. To reduce these inelastic losses, we applied evaporative cooling and demonstrated a creation of two-dimensional atomic gases.

AIP conference proceedings•Jan 1, 2001•12 citations

Recoil-Limited Laser Cooling of Sr87 Atoms near the Fermi Temperature

Takashi Mukaiyama, Hidetoshi Katori, T. Ido +2 more

A dynamic magneto-optical trap, which relies on the rapid randomization of population in Zeeman substates, has been demonstrated for fermionic strontium atoms on the $^{1}S_{0}\ensuremath{-}^{3}P_{1}$ intercombination transition. The obtained sample, $1\ifmmode\times\else\texttimes\fi{}{10}^{6}$ atoms at a temperature of $2\text{ }\ensuremath{\mu}\mathrm{K}$ in the trap, was further Doppler cooled and polarized in a far-off resonant optical lattice to achieve 2 times the Fermi temperature.

Physical Review Letters•Mar 20, 2003•131 citations

Optical-dipole trapping of Sr atoms at a high phase-space density

T. Ido, Yoshitomo Isoya, Hidetoshi Katori

Employing a far-off resonance optical-dipole trap (FORT), we attained a phase-space density exceeding 0.1, or an order to quantum degeneracy. Strontium atoms were magneto-optically cooled and trapped using the spin-forbidden ${}^{1}{S}_{0}{\ensuremath{-}}^{3}{P}_{1}$ transition and then compressed into a FORT that was designed to allow simultaneous Doppler cooling. We discussed that the phase-space density was finally limited by the light-assisted collisions occurring in the optical cooling.

Physical Review A•May 2, 2000•103 citations

Steady-state magneto-optical trap of fermionic strontium on a narrow-line transition

Rodrigo González Escudero, Chun-Chia Chen, Shayne Bennetts +2 more

A steady-state magneto-optical trap (MOT) of fermionic strontium atoms operating on the $7.5\text{-kHz}$-wide $^{1}S_{0}\text{\ensuremath{-}}^{3}P_{1}$ transition is demonstrated. This MOT contains $8.4\ifmmode\times\else\texttimes\fi{}{10}^{7}\phantom{\rule{0.16em}{0ex}}\mathrm{atoms}$, a loading rate of $1.3\ifmmode\times\else\texttimes\fi{}{10}^{7}\phantom{\rule{0.16em}{0ex}}\mathrm{atoms}/\mathrm{s}$, and an average temperature of $12\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{K}$. These parameters make it well suited to serve as a source of atoms for continuous-wave superradiant lasers operating on strontium's mHz-wide clock transition. Such lasers have only been demonstrated using pulsed Sr sources, limiting their range of applications. Our MOT makes an important step toward continuous operation of these devices, paving the way for continuous active optical clocks.

arXiv:2104.06814•Physical Review Research•Aug 16, 2021•13 citations

Magnetic trapping of metastable 3P2 atomic strontium

Sarah Nagel, Clayton E. Simien, S. Laha +3 more

We report the magnetic trapping of metastable ${}^{3}{P}_{2}$ atomic strontium. Atoms are cooled in a magneto-optical trap (MOT) operating on the dipole-allowed ${}^{1}{S}_{0}{\ensuremath{-}}^{1}{P}_{1}$ transition at 461 nm. Decay via ${}^{1}{\stackrel{\ensuremath{\rightarrow}}{{P}_{1}}}^{1}{\stackrel{\ensuremath{\rightarrow}}{{D}_{2}}}^{3}{P}_{2}$ continuously loads a magnetic trap formed by the quadrupole magnetic field of the MOT. Over ${10}^{8}$ atoms at a density of $8\ifmmode\times\else\texttimes\fi{}{10}^{9}{\mathrm{cm}}^{\ensuremath{-}3}$ and temperature of 1 mK are trapped. The atom temperature is significantly lower than what would be expected from the kinetic and potential energies of atoms as they are transferred from the MOT. This suggests the occurrence of thermalization and evaporative cooling in the magnetic trap.

arXiv:physics/0212024•Physical Review A•Jan 13, 2003•96 citations
We report narrow-line laser cooling and trapping of strontium atoms down to the photon recoil temperature. 88Sr{}^{88}\mathrm{Sr}88Sr atoms precooled by the broad 1S0\ensuremath−1P1^{1}S_{0}\ensuremath{-}^{1}P_{1}1S0​\ensuremath−1P1​ transition at 461 nm were further cooled in a magneto-optical trap using the spin-forbidden transition 1S0\ensuremath−3P1^{1}S_{0}\ensuremath{-}^{3}P_{1}1S0​\ensuremath−3P1​ at 689 nm. We have thus obtained an atomic sample with a density over 1012cm\ensuremath−3{10}^{12}\mathrm{cm}{}^{\ensuremath{-}3}1012cm\ensuremath−3 and a minimum temperature of 400 nK, corresponding to a maximum phase space density of 10\ensuremath−2{10}^{\ensuremath{-}2}10\ensuremath−2 which is 3 orders of magnitude larger than the value that has been obtained by magneto-optical traps to date. This scheme provides us an opportunity and system to study quantum statistical properties of degenerate fermions as well as bosons.
Summary form only given. All-optical production of quantum degenerate atomic gases has been one of the long-standing targets in laser cooling. We report a novel approach towards this direction based on a narrow-line laser cooling for strontium atoms. By employing two transitions with markedly different dipole moments, i.e., the allowed /sup 1/S/sub 0/-/sup 1/P/sub 1/ (/spl lambda/=461 nm, /spl gamma/=2/spl pi//spl times/32 MHz) and the spin-forbidden /sup 1/S/sub 0/-/sup 3/P/sub 1/ (/spl lambda/=689 nm, /spl gamma/=2/spl pi//spl times/7.6 kHz) transition, thermal strontium atoms were Doppler-cooled down to 400 nK or the photon recoil temperature, in a magneto-optical trap (MOT). Presents the corresponding energy levels for cooling and trapping. The use of a narrow spin-forbidden transition successfully reduced the radiation trapping effects at a high atom density over 10/sup 12//cm/sup 3/, thus enabling us to attain the hitherto high phase space density of 0.01 in a MOT.
We report on a narrow-line laser cooling and trapping of strontium atoms near quantum degeneracy. Employing a magneto-optical trap (MOT) on the spin-forbidden transition 1S0−3P1 at 689 nm, we have laser-cooled an atomic sample down to the photon recoil temperature of 400 nK with a phase space density of 10−2. The atoms were then compressed into a new type of far-off resonance optical dipole trap that was designed to allow simultaneous Doppler cooling, resulting in a phase space density of 10% to that required for quantum degeneracy. It is shown that this value is finally limited by light-assisted collisions occurring in the optical cooling. To reduce these inelastic losses, we applied evaporative cooling and demonstrated a creation of two-dimensional atomic gases.
A dynamic magneto-optical trap, which relies on the rapid randomization of population in Zeeman substates, has been demonstrated for fermionic strontium atoms on the $^{1}S_{0}\ensuremath{-}^{3}P_{1}$ intercombination transition. The obtained sample, $1\ifmmode\times\else\texttimes\fi{}{10}^{6}$ atoms at a temperature of $2\text{ }\ensuremath{\mu}\mathrm{K}$ in the trap, was further Doppler cooled and polarized in a far-off resonant optical lattice to achieve 2 times the Fermi temperature.
Employing a far-off resonance optical-dipole trap (FORT), we attained a phase-space density exceeding 0.1, or an order to quantum degeneracy. Strontium atoms were magneto-optically cooled and trapped using the spin-forbidden ${}^{1}{S}_{0}{\ensuremath{-}}^{3}{P}_{1}$ transition and then compressed into a FORT that was designed to allow simultaneous Doppler cooling. We discussed that the phase-space density was finally limited by the light-assisted collisions occurring in the optical cooling.
A steady-state magneto-optical trap (MOT) of fermionic strontium atoms operating on the 7.5-kHz7.5\text{-kHz}7.5-kHz-wide $^{1}S_{0}\text{\ensuremath{-}}^{3}P_{1}$ transition is demonstrated. This MOT contains $8.4\ifmmode\times\else\texttimes\fi{}{10}^{7}\phantom{\rule{0.16em}{0ex}}\mathrm{atoms}$, a loading rate of $1.3\ifmmode\times\else\texttimes\fi{}{10}^{7}\phantom{\rule{0.16em}{0ex}}\mathrm{atoms}/\mathrm{s}$, and an average temperature of $12\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{K}$. These parameters make it well suited to serve as a source of atoms for continuous-wave superradiant lasers operating on strontium's mHz-wide clock transition. Such lasers have only been demonstrated using pulsed Sr sources, limiting their range of applications. Our MOT makes an important step toward continuous operation of these devices, paving the way for continuous active optical clocks.
We report the magnetic trapping of metastable 3P2{}^{3}{P}_{2}3P2​ atomic strontium. Atoms are cooled in a magneto-optical trap (MOT) operating on the dipole-allowed ${}^{1}{S}_{0}{\ensuremath{-}}^{1}{P}_{1}$ transition at 461 nm. Decay via ${}^{1}{\stackrel{\ensuremath{\rightarrow}}{{P}_{1}}}^{1}{\stackrel{\ensuremath{\rightarrow}}{{D}_{2}}}^{3}{P}_{2}$ continuously loads a magnetic trap formed by the quadrupole magnetic field of the MOT. Over 108{10}^{8}108 atoms at a density of $8\ifmmode\times\else\texttimes\fi{}{10}^{9}{\mathrm{cm}}^{\ensuremath{-}3}$ and temperature of 1 mK are trapped. The atom temperature is significantly lower than what would be expected from the kinetic and potential energies of atoms as they are transferred from the MOT. This suggests the occurrence of thermalization and evaporative cooling in the magnetic trap.