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

Adiabatic cooling of atoms by an intense standing wave

Jian Chen, J. G. Story, J. J. Tollett, Randall G. Hulet

Published Aug 31, 1992• 58 citations
Publisher

Abstract

Lithium atoms channeled in the nodes of an intense standing-wave radiation field are cooled to near the recoil limit by adibatically reducing the radiation intensity. The final momentum distribution has a narrow component with a root-mean-squared momentum of 2\ensuremath{\Elzxh}k in one dimension, where \ensuremath{\Elzxh}k is the momentum of a radiation-field photon. The data are compared with the results of a Monte Carlo simulation using a two-level atom model. This process may be useful for cooling and increasing the phase-space density of atoms confined in a magnetic trap.

DOI
10.1103/physrevlett.69.1344

Related papers

Investigation of Atomic Motion in AN Intense Standing Light Wave and Application to Adiabatic Laser Cooling of Atoms.

Jian Chen

The effect of the dipole force and its fluctuation on the motion of Li atoms in an intense, one-dimensional, near-resonant standing light wave has been investigated, both theoretically and experimentally. The duration of the interaction of the atoms with the standing wave was varied from several tens of spontaneous emission lifetimes to several hundred. For a standing wave frequency blue-detuned from resonance, diffusive heating can dominate the time-averaged dissipative dipole force so that there is no steady-state momentum distribution. However, for sufficiently large blue detunings the rate of diffusion is so slow that the resulting distribution approaches a quasi-steady state. For red detunings the diffusion is balanced with the force and a true steady-state is achieved. A Monte Carlo method based on the density matrix equations in the dressed-state representation is applied to simulate the atomic motion. The dynamics of atom channeling is studied. One of the important applications of this investigation is adiabatic laser cooling of atoms. Lithium atoms channeled in the nodes of an intense standing wave radiation field are cooled to near the recoil limit, a single photon's momentum $\\hbar{k}$, by adiabatically reducing the radiation intensity. The final momentum distribution has a narrow component with a root mean squared momentum of 2 $\\hbar{k}$ in one-dimension. The data are compared with the results obtained by the Monte Carlo method. This process may be useful for cooling and increasing the phase-space density of atoms confined in a magnetic trap.

•Jan 1, 1993•0 citations

Adiabatic cooling of atoms by an intense standing wave

J. G. Story, J. Chen, Randall G. Hulet

An atom slowly moving in a standing wave can be confined to, or in, the nodes of the standing wave if the atom’s kinetic energy is less than the depth of the potential formed by the interaction of the atom with the standing-wave radiation.1 We have observed a significant cooling of channeled atoms in one dimension resulting from an adiabatic turn-off of the standing-wave intensity.

Quantum Electronics and Laser Science Conference•May 10, 1992•0 citations

Strong Gaussian standing wave: an efficient tool for laser cooling of atomic beams

Pavel Zemánek, Christopher J. Foot

We propose an efficient method of cooling atoms in a strong Gaussian standing wave. The steep gradients of the atomic potential energy give rise to large dipole forces, which can be much stronger than the maximum radiation pressure force and can therefore stop atoms in a much shorter distance. We have simulated the cooling process using a semi-classical Monte- Carlo method, which includes the radial motion, in addition to the motion along the beams. Both motions are calculated directly without separation the dynamics into force and diffusion terms. To cool a large range of atomic velocities the frame in which the standing wave is at rest was swept by changing the frequencies of the counter-propagating beams, in a similar way to the well-known chirp cooling technique using the radiation pressure force. If the curvature of Gaussian beams far from beam waist is employed the radial motion and velocities can be reduced even for the blue detuning comparing to the near waist case. The simulations show that it is possible to stop caesium atoms in a distance of several centimeters (the exact value depends on the laser power, beam waist radius and acceptable chirping force) starting from the most probable velocity at room temperature. Narrower radial and wider axial velocity distribution was obtained for red detuning comparing with the blue one.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jan 1, 1998•3 citations

Calculations on cooling of fast, multilevel atoms by intense laser fields

Ejvind Bonderup, Klaus Mølmer

As a theoretical background for an ongoing experiment on longitudinal cooling of an energetic atomic beam by an intense laser field, we generalize the dressed-atom description of the atom–laser interaction from a two-level to a multilevel system. Expressions are presented for the average force on the atom, in particular in the limits of high and low velocities with respect to a standing wave, and the influence of fluctuations is studied through a Monte Carlo simulation. Appreciable cooling is predicted for a beam of 200-eV neon atoms traversing a 75-cm-long resonator in which the energy density is maintained by two 0.5-W cw lasers.

Journal of the Optical Society of America B•Nov 1, 1989•8 citations

Cooling and trapping of three-level atoms in a bichromatic standing wave

Han Pu, Tianwu Cai, N. P. Bigelow +2 more

We show that a three-level atom in the cascade configuration can be stably trapped and cooled in one dimension by an intense bichromatic standing wave. At the two-photon resonance, rectified dipole forces result in a deep potential well which can be used to localize the atoms in space. In the vicinity of the rectified potential minimum, the spatial dependence of the dressed state energies can lead to a velocity dependence of the force which produces damping of the atomic motion. Consideration of the heating effects of momentum diffusion indicates that cooling and stable trapping at low temperatures is possible in such a bichromatic field.

Optics Communications•Jul 1, 1995•14 citations

Laser cooling of lithium atoms by a strong standing wave

J. J. Tollett, Jian Chen, C. C. Bradley +3 more

An atom moving in a strong standing wave radiation field may be translationally cooled by the induced or dipole force.1 The dipole force is proportional to I1/2, where I is the laser intensity, whereas the Doppler (usual) cooling force saturates with increasing I. Since laser sources can provide intensities which are much greater than the saturation intensities of many atomic transitions, cooling via the dipole force can be much more efficient than Doppler cooling. The dipole force has been used to cool the transverse2,3 and the longitudinal4 velocities of atoms in an atomic beam.

•May 21, 1990•0 citations
Lithium atoms channeled in the nodes of an intense standing-wave radiation field are cooled to near the recoil limit by adibatically reducing the radiation intensity. The final momentum distribution has a narrow component with a root-mean-squared momentum of 2\ensuremath{\Elzxh}k in one dimension, where \ensuremath{\Elzxh}k is the momentum of a radiation-field photon. The data are compared with the results of a Monte Carlo simulation using a two-level atom model. This process may be useful for cooling and increasing the phase-space density of atoms confined in a magnetic trap.
The effect of the dipole force and its fluctuation on the motion of Li atoms in an intense, one-dimensional, near-resonant standing light wave has been investigated, both theoretically and experimentally. The duration of the interaction of the atoms with the standing wave was varied from several tens of spontaneous emission lifetimes to several hundred. For a standing wave frequency blue-detuned from resonance, diffusive heating can dominate the time-averaged dissipative dipole force so that there is no steady-state momentum distribution. However, for sufficiently large blue detunings the rate of diffusion is so slow that the resulting distribution approaches a quasi-steady state. For red detunings the diffusion is balanced with the force and a true steady-state is achieved. A Monte Carlo method based on the density matrix equations in the dressed-state representation is applied to simulate the atomic motion. The dynamics of atom channeling is studied. One of the important applications of this investigation is adiabatic laser cooling of atoms. Lithium atoms channeled in the nodes of an intense standing wave radiation field are cooled to near the recoil limit, a single photon's momentum hbark\\hbar{k}hbark, by adiabatically reducing the radiation intensity. The final momentum distribution has a narrow component with a root mean squared momentum of 2 hbark\\hbar{k}hbark in one-dimension. The data are compared with the results obtained by the Monte Carlo method. This process may be useful for cooling and increasing the phase-space density of atoms confined in a magnetic trap.
We propose an efficient method of cooling atoms in a strong Gaussian standing wave. The steep gradients of the atomic potential energy give rise to large dipole forces, which can be much stronger than the maximum radiation pressure force and can therefore stop atoms in a much shorter distance. We have simulated the cooling process using a semi-classical Monte- Carlo method, which includes the radial motion, in addition to the motion along the beams. Both motions are calculated directly without separation the dynamics into force and diffusion terms. To cool a large range of atomic velocities the frame in which the standing wave is at rest was swept by changing the frequencies of the counter-propagating beams, in a similar way to the well-known chirp cooling technique using the radiation pressure force. If the curvature of Gaussian beams far from beam waist is employed the radial motion and velocities can be reduced even for the blue detuning comparing to the near waist case. The simulations show that it is possible to stop caesium atoms in a distance of several centimeters (the exact value depends on the laser power, beam waist radius and acceptable chirping force) starting from the most probable velocity at room temperature. Narrower radial and wider axial velocity distribution was obtained for red detuning comparing with the blue one.
As a theoretical background for an ongoing experiment on longitudinal cooling of an energetic atomic beam by an intense laser field, we generalize the dressed-atom description of the atom–laser interaction from a two-level to a multilevel system. Expressions are presented for the average force on the atom, in particular in the limits of high and low velocities with respect to a standing wave, and the influence of fluctuations is studied through a Monte Carlo simulation. Appreciable cooling is predicted for a beam of 200-eV neon atoms traversing a 75-cm-long resonator in which the energy density is maintained by two 0.5-W cw lasers.
We show that a three-level atom in the cascade configuration can be stably trapped and cooled in one dimension by an intense bichromatic standing wave. At the two-photon resonance, rectified dipole forces result in a deep potential well which can be used to localize the atoms in space. In the vicinity of the rectified potential minimum, the spatial dependence of the dressed state energies can lead to a velocity dependence of the force which produces damping of the atomic motion. Consideration of the heating effects of momentum diffusion indicates that cooling and stable trapping at low temperatures is possible in such a bichromatic field.
An atom moving in a strong standing wave radiation field may be translationally cooled by the induced or dipole force.1 The dipole force is proportional to I1/2, where I is the laser intensity, whereas the Doppler (usual) cooling force saturates with increasing I. Since laser sources can provide intensities which are much greater than the saturation intensities of many atomic transitions, cooling via the dipole force can be much more efficient than Doppler cooling. The dipole force has been used to cool the transverse2,3 and the longitudinal4 velocities of atoms in an atomic beam.