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

Journal of Experimental and Theoretical Physics

Magnetooptical compression of atomic beams

V. I. Balykin, Vladimir G. Minogin

Published Jan 1, 2003• 3 citations
Publisher

Abstract

We consider the propagation of an atomic beam in a quadrupole magnetic field under transverse irradiation by a cooling laser field. The cooling laser field was chosen in the form of a two-dimensional σ + -σ − configuration. We show that the sub-Doppler resonance in the radiation force can be used to reduce the diameter of the atomic beam to a value on the order of 10 mm. We establish that the simultaneous transverse cooling and compression of the atomic beam allow its phase density to be increased to values of the order of 10 −4 –10 −3 . The dipole interaction of an atom with the cooling and compressing laser field in a quadrupole magnetic field is analyzed in terms of a simple (3 + 5)-level model atom.

DOI
10.1134/1.1545378

Related papers

Sharp Focusing of an Atomic Beam with the Doppler and Sub-Doppler Laser Cooling Mechanisms in a Two-Dimensional Magneto-Optical Trap

Dar'ya V. Bykova, Anton E. Afanasiev, V. I. Balykin

The focusing of an atomic beam with the use of a two-dimensional magneto-optical trap in order to increase the number of atoms in the region of their laser cooling and localization near an atom chip is discussed. Two regimes of the interaction of atoms with a focusing laser field are considered: (i) the Doppler interaction regime, which occurs at small detunings of the laser field from the atomic resonance, and (ii) the sub-Doppler interaction regime, which occurs at large detunings of the laser field from the atomic resonance. The efficiency of focusing in the first case is low because of the momentum diffusion. It has been shown that the momentum diffusion in the sub-Doppler cooling mechanism is insignificant and, as a result, the broadening of the transverse velocity distribution of atoms is small. The sharp focusing of the atomic beam is possible in this interaction regime.

Journal of Experimental and Theoretical Physics Letters•Jul 1, 2023•7 citations

Transverse magneto-optical compression of a frequency-chirping, slowed cesium atomic beam

Jia Yu, J. Djemaa, P. Nosbaum +1 more

We have transversally compressed a monokinetic cesium atomic beam in a 2D MOT1,2 on the F=4→F′=5 transition of the cesium IX, line. The longitudinal cooling was obtained by frequency-chirped diode lasers.3 Preliminary results have been obtained showing a final diameter of about 50pm and a density of 108at./cm3. We have studied the specificities of a multi-V system as the transition F=4→F′=5 in the cesium atom. Originally proposed for a three-level V-type atomic system4, the process can be easily generalized to F→F+1 (F>=1) transitions. In this case, the atom is assumed to be polarized into the Zeeman sub-level Mf=-F with respect to the local magnetic field inside of the trap. For a non-polarized statistic mixture, two effects modify the compression process. The first one is due to the large variation in the Clebsch-Gordan coefficients.3 The second one comes from the difference between the Larmor frequencies associated to the lower and the upper levels. The both effects lead to a mF-dependent restoring force. Efficient compression can be obtained by preparing the atomic population in the “good” Zeeman sub-levels, |MF|=F. Two methods have been explored in our experiments to polarize the atomic beam. The first one used an additional blue-detuned laser beam to increase the atomic population in the |MF|=f Zeeman sub-levels by optical pumping. In the second one, the σ-polarized cooling laser beam orientated the atomic population in the axial direction during the slowing process. This orientation was adiabatically transformed into transversal ones by entering in the trap. Further experiments are in progress.

Annual Meeting Optical Society of America•Jan 1, 1993•0 citations

Pulsed magnetooptic compression of cold atoms

V. I. Balykin

A method is proposed for increasing the density of cold atoms. The method is based on pulsed laser irradiation of the atoms in a nonuniform magnetic field. The interaction conditions under which the velocity of an atom is damped to a value that depends only on the magnitude of the magnetic field and the position of the atom at the moment it is irradiated by the laser field are found. The atom completely loses all memory of its initial coordinates and velocity. In a three-dimensional interaction geometry an irradiated atomic ensemble transforms into an ensemble contracting toward the origin. The basic physical processes accompanying the compression of atoms are studied.

Journal of Experimental and Theoretical Physics Letters•Sep 1, 1997•9 citations

Laser sub-Doppler cooling of atoms in an arbitrarily directed magnetic field

Soo Chang, Taeg Yong Kwon, Ho Seong Lee +1 more

We analyze the influence of an arbitrarily directed uniform magnetic field on the laser sub-Doppler cooling of atoms. The analysis is done for a (3+5)-level atom excited by a ${\ensuremath{\sigma}}^{+}\ensuremath{-}{\ensuremath{\sigma}}^{\ensuremath{-}}$ laser field configuration. Our analysis shows that the effects of the magnetic field depend strongly on the direction of the magnetic field. In an arbitrarily directed magnetic field the laser cooling configuration produces both the main resonance existing already at zero magnetic field and additional sub-Doppler resonances caused by two-photon and higher-order multiphoton processes. These sub-Doppler resonances are, however, well separated on the velocity scale if the Zeeman shift exceeds the widths of the resonances. This allows one to use the main sub-Doppler resonance for an effective laser cooling of atoms even in the presence of the magnetic field. The effective temperature of the atomic ensemble at the velocity of the main resonance is found to be almost the same as in the absence of the magnetic field. The defined structure of the multiphoton resonances may be of importance for the sub-Doppler laser cooling of atoms, atomic extraction from magneto-optical traps, and applications related to the control of atomic motion.

Physical Review A•Oct 4, 2002•7 citations

Observation of a New Magneto-optical Trap

Olivier Émile, F Bardou, Ch Salomon +3 more

We report on the observation of a new laser trap for neutral atoms. It uses three orthogonal pairs of counterpropagating laser beams having linear polarizations at 45° and a quadrupole magnetic field. 10 8 cesium atoms were thus confined in a 0.15 mm 3 volume at a temperature of 60 μK, a factor of 2 below the Doppler cooling limit. We interpret this trapping as being due to the new magneto-optical force recently observed by Grimm et al. and which is essentially a dipole force rectified by the magnetic field. This trap opens new possibilities for increasing the phase-space density of laser-cooled atoms.

Europhysics Letters (EPL)•Dec 15, 1992•29 citations

Ostraya fokusirovka atomnogo puchka s ispol'zovaniem doplerovskogo i sub-doplerovskogo mekhanizmov lazernogo okhlazhdeniya v dvumernoy magnito-opticheskoy lovushke

Dar'ya V. Bykova, А. Е. Афанасьев, V. I. Balykin

The focusing of an atomic beam with the use of a two-dimensional magneto-optical trap in order to increase the number of atoms in the region of their laser cooling and localization near an atom chip is discussed. Two regimes of the interaction of atoms with a focusing laser field are considered: (i) the Doppler interaction regime, which occurs at small detunings of the laser field from the atomic resonance, and (ii) the sub-Doppler interaction regime, which occurs at large detunings of the laser field from the atomic resonance. The efficiency of focusing in the first case is low because of the momentum diffusion. It has been shown that the momentum diffusion in the sub-Doppler cooling mechanism is insignificant and, as a result, the broadening of the transverse velocity distribution of atoms is small. The sharp focusing of the atomic beam is possible in this interaction regime.

Письма в Журнал экспериментальной и теоретической физики•Dec 15, 2023•1 citation
We consider the propagation of an atomic beam in a quadrupole magnetic field under transverse irradiation by a cooling laser field. The cooling laser field was chosen in the form of a two-dimensional σ + -σ − configuration. We show that the sub-Doppler resonance in the radiation force can be used to reduce the diameter of the atomic beam to a value on the order of 10 mm. We establish that the simultaneous transverse cooling and compression of the atomic beam allow its phase density to be increased to values of the order of 10 −4 –10 −3 . The dipole interaction of an atom with the cooling and compressing laser field in a quadrupole magnetic field is analyzed in terms of a simple (3 + 5)-level model atom.
The focusing of an atomic beam with the use of a two-dimensional magneto-optical trap in order to increase the number of atoms in the region of their laser cooling and localization near an atom chip is discussed. Two regimes of the interaction of atoms with a focusing laser field are considered: (i) the Doppler interaction regime, which occurs at small detunings of the laser field from the atomic resonance, and (ii) the sub-Doppler interaction regime, which occurs at large detunings of the laser field from the atomic resonance. The efficiency of focusing in the first case is low because of the momentum diffusion. It has been shown that the momentum diffusion in the sub-Doppler cooling mechanism is insignificant and, as a result, the broadening of the transverse velocity distribution of atoms is small. The sharp focusing of the atomic beam is possible in this interaction regime.
We have transversally compressed a monokinetic cesium atomic beam in a 2D MOT1,2 on the F=4→F′=5 transition of the cesium IX, line. The longitudinal cooling was obtained by frequency-chirped diode lasers.3 Preliminary results have been obtained showing a final diameter of about 50pm and a density of 108at./cm3. We have studied the specificities of a multi-V system as the transition F=4→F′=5 in the cesium atom. Originally proposed for a three-level V-type atomic system4, the process can be easily generalized to F→F+1 (F>=1) transitions. In this case, the atom is assumed to be polarized into the Zeeman sub-level Mf=-F with respect to the local magnetic field inside of the trap. For a non-polarized statistic mixture, two effects modify the compression process. The first one is due to the large variation in the Clebsch-Gordan coefficients.3 The second one comes from the difference between the Larmor frequencies associated to the lower and the upper levels. The both effects lead to a mF-dependent restoring force. Efficient compression can be obtained by preparing the atomic population in the “good” Zeeman sub-levels, |MF|=F. Two methods have been explored in our experiments to polarize the atomic beam. The first one used an additional blue-detuned laser beam to increase the atomic population in the |MF|=f Zeeman sub-levels by optical pumping. In the second one, the σ-polarized cooling laser beam orientated the atomic population in the axial direction during the slowing process. This orientation was adiabatically transformed into transversal ones by entering in the trap. Further experiments are in progress.
A method is proposed for increasing the density of cold atoms. The method is based on pulsed laser irradiation of the atoms in a nonuniform magnetic field. The interaction conditions under which the velocity of an atom is damped to a value that depends only on the magnitude of the magnetic field and the position of the atom at the moment it is irradiated by the laser field are found. The atom completely loses all memory of its initial coordinates and velocity. In a three-dimensional interaction geometry an irradiated atomic ensemble transforms into an ensemble contracting toward the origin. The basic physical processes accompanying the compression of atoms are studied.
We analyze the influence of an arbitrarily directed uniform magnetic field on the laser sub-Doppler cooling of atoms. The analysis is done for a (3+5)-level atom excited by a ${\ensuremath{\sigma}}^{+}\ensuremath{-}{\ensuremath{\sigma}}^{\ensuremath{-}}$ laser field configuration. Our analysis shows that the effects of the magnetic field depend strongly on the direction of the magnetic field. In an arbitrarily directed magnetic field the laser cooling configuration produces both the main resonance existing already at zero magnetic field and additional sub-Doppler resonances caused by two-photon and higher-order multiphoton processes. These sub-Doppler resonances are, however, well separated on the velocity scale if the Zeeman shift exceeds the widths of the resonances. This allows one to use the main sub-Doppler resonance for an effective laser cooling of atoms even in the presence of the magnetic field. The effective temperature of the atomic ensemble at the velocity of the main resonance is found to be almost the same as in the absence of the magnetic field. The defined structure of the multiphoton resonances may be of importance for the sub-Doppler laser cooling of atoms, atomic extraction from magneto-optical traps, and applications related to the control of atomic motion.
We report on the observation of a new laser trap for neutral atoms. It uses three orthogonal pairs of counterpropagating laser beams having linear polarizations at 45° and a quadrupole magnetic field. 10 8 cesium atoms were thus confined in a 0.15 mm 3 volume at a temperature of 60 μK, a factor of 2 below the Doppler cooling limit. We interpret this trapping as being due to the new magneto-optical force recently observed by Grimm et al. and which is essentially a dipole force rectified by the magnetic field. This trap opens new possibilities for increasing the phase-space density of laser-cooled atoms.
The focusing of an atomic beam with the use of a two-dimensional magneto-optical trap in order to increase the number of atoms in the region of their laser cooling and localization near an atom chip is discussed. Two regimes of the interaction of atoms with a focusing laser field are considered: (i) the Doppler interaction regime, which occurs at small detunings of the laser field from the atomic resonance, and (ii) the sub-Doppler interaction regime, which occurs at large detunings of the laser field from the atomic resonance. The efficiency of focusing in the first case is low because of the momentum diffusion. It has been shown that the momentum diffusion in the sub-Doppler cooling mechanism is insignificant and, as a result, the broadening of the transverse velocity distribution of atoms is small. The sharp focusing of the atomic beam is possible in this interaction regime.