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

Siberian Journal of Physics

Study of a Possibility of Deep Laser Cooling of Magnesium Atoms for Designing the New-Generation Frequency Standard

Denis V. Brazhnikov, A E Bonert, Andrei Goncharov, А. В. Тайченачев, Anatolii M Tumaikin, Valeriy I. Yudin, M. Yu. Basalaev, R. Ya. Ilenkov, Aleksandr Shilov

Published Dec 1, 2012• 0 citations
Publisher

Abstract

Theoretical analysis of sub-Doppler laser cooling of 24Mg atoms using 33 P2 → 33 D3 transition in the field of two counterpropagating light waves with opposite circular polarizations is presented. The standard semi-classical approach based on the Fokker-Plank equation is exploited for numerical modeling of laser cooling. The problem is solved out of limits of slow atom approximation and for arbitrary light intensity. The dependences of light force and diffusion on an atomic velocity are studied for various frequency detuning and Rabi frequency. Also, to obtain optimal parameters of laser cooling, the atomic velocity distributions are investigated for various conditions and the dependence of average atomic kinetic energy on the light field intensity and frequency detuning is calculated. In the case of strong field a multi-spike velocity distribution profile is observed. It results from various nonlinear effects accompany absorption of laser photons by atoms. In conclusion we make additional recommendations to increase atoms in metastable state 33 P2, what is necessary for effective laser cooling

DOI
10.54362/1818-7919-2012-7-4-6-18

Related papers

Deep laser cooling of magnesium atoms using a 33P2→33D3dipole transition

Denis V. Brazhnikov, A E Bonert, Andrei Goncharov +2 more

We present the theoretical analysis of sub-Doppler laser cooling of 24Mg atoms using dipole transition 33P2→33D3 under two counterpropagating light waves with opposite circular polarizations (one-dimensional σ+σ– configuration). For numerical calculations the standard semi-classical approach based on the Fokker–Planck equation for linear momentum distribution of atoms is exploited. The distributions are gained beyond the limits of slow atoms approximation and for an arbitrary light field intensity. The absence of these limits allows us to determine the optimal parameters of the light field to maximize a fraction of ultracold atoms (T ~ 10 μK) in a whole atomic cloud. In particular, under certain conditions the fraction can reach a value of 50%. Solution of the existing problems in deep laser cooling of magnesium atoms has obvious prospects for atomic optics and quantum metrology: for instance, in designing new-generation optical frequency and time standards based on cold atoms in optical lattices.

Laser Physics•May 29, 2014•7 citations

Quantum treatment of two-stage sub-Doppler laser cooling of magnesium atoms

Прудников Олег Николаевич, Denis V. Brazhnikov, А. В. Тайченачев +4 more

Deep laser cooling of $^{24}\mathrm{Mg}$ atoms has been theoretically studied. We propose a two-stage sub-Doppler cooling strategy using electrodipole transition $3\phantom{\rule{0.16em}{0ex}}{}^{3}{P}_{2}\ensuremath{\rightarrow}3\phantom{\rule{0.16em}{0ex}}{}^{3}{D}_{3}$ ($\ensuremath{\lambda}\phantom{\rule{0.16em}{0ex}}=\phantom{\rule{0.16em}{0ex}}383.8$ nm). The first stage implies exploiting magneto-optical trap with ${\ensuremath{\sigma}}^{+}$ and ${\ensuremath{\sigma}}^{\ensuremath{-}}$ light beams, while at the second stage lin $\ensuremath{\perp}$ lin molasses is used. We focus on achieving a large number of ultracold atoms (${T}_{\mathrm{eff}}<10 \ensuremath{\mu}\mathrm{K}$) in a cold-atomic cloud. The calculations have been based on quantum treatment, taking into full account the recoil effect and beyond many widely used approximations. Steady-state values of average kinetic energy and linear momentum distributions of cold atoms have been analyzed for various light-field intensities and frequency detunings. The results of conducted quantum analysis have been significantly different from the results achieved under a semiclassical approximation based on the Fokker-Planck equation. The second cooling stage allows achieving sufficiently lower kinetic energies of the atomic cloud as well as increased fraction of ultracold atoms at certain conditions compared to the first one. We hope that the obtained results can help in overcoming current experimental problems in deep cooling of $^{24}\mathrm{Mg}$ atoms by means of laser field. Cold magnesium atoms cooled in a large amount to several $\ensuremath{\mu}\mathrm{K}$ are of huge interest to, for example, quantum metrology and to other many-body cold-atoms physics.

arXiv:1508.03694•Physical Review A•Dec 15, 2015•17 citations

Laser Cooling Dynamics of Neutral Atoms in a Light Field with Nonuniform Polarization for Fixed Interaction Time

Прудников Олег Николаевич

Laser cooling dynamics of neutral atoms with a closed optical transition Jg → Je in light fields with nonuniform polarization formed by counterpropagating waves with linear, circular or elliptical polarization was considered. For the case of finite interaction time of atoms with light field both mechanisms of Doppler and Sub-Doppler laser cooling affected on atoms in ensemble having different velocities were taken into account. We get qualitative relations on a base of numerical analysis in a frame of quasiclassical treatment of laser cooling. These relations allow to define optimal parameters of cooling waves, i.e. polarization, detuning from atomic resonance and intensity of light waves for the most rapid and dip laser cooling from initially wide momentum distribution for finite interaction time of atoms with laser field

Siberian Journal of Physics•Mar 1, 2011•0 citations

Atom cooling in one dimension with high-intensity laser light

M. R. Williams, M. J. Bellanca, L. Liu +4 more

In sub-Doppler laser cooling of atoms, the lowest temperatures are known to occur at low (but not too low) excitation, and the temperature increases roughly linearly with laser intensity. However, under conditions for which the lowest temperatures are obtained, the small velocity capture range and low optical pumping rate limit the number of atoms that can be collected into the cold sample. In this study, we present measurements for laser cooling of Rb and metastable He atoms for two counterpropagating laser beams with orthogonal linear polarization (lin\ensuremath{\perp}lin) over a wide range of saturation parameters and laser detunings, together with results of semiclassical (Fokker-Planck) and quantum density matrix calculations. We find that at higher laser intensity, a larger number of atoms can be collected into a final velocity distribution that is significantly narrower than that given by a linear extrapolation vs the square root of laser intensity. Two cooling mechanisms are at work: the sub-Doppler Sisyphus mechanism and also Doppler cooling. Under certain conditions that we discuss, Doppler cooling aids Sisyphus cooling by collecting high-velocity atoms beyond the Sisyphus capture range. ${\mathrm{He}}^{*}$ presents a rather unusual situation in that the minimum average kinetic energy ${(E}_{\mathrm{av}})$ for purely Sisyphus cooling is comparable to the minimum value of ${E}_{\mathrm{av}}$ with Doppler cooling alone.

Physical Review A•Jan 1, 1998•7 citations

One-dimensional sub- Doppler laser cooling

Vladimir Finkelstein, P. R. Berman, Jingzhong Guo

A theoretical analysis is given for 1-D laser cooling below the Doppler limit of J = 1/2 ground- state atoms. The laser field consists of a pair of counterpropagating, linearly polarized low- power beams, whose polarization directions differ by an angle θ (0 ≤ θ ≤ π/2). For θ ≪ 1, the effective optical pumping time is shown to increase strongly near the nodes of the standing wave and the cooling force can be much larger than that for θ ~1. Moreover, for θ ≪ 1, it can be shown that the stimulated part of the atomic diffusion is reduced considerably as compared with that for θ ~ 1. As a consequence it is possible to achieve an equilibrium atomic distribution that, for θ ≪ 1, is characterized by a mean kinetic energy lower than that predicted to occur for θ = π/2. The equilibrium velocity distribution is not necessarily Maxwellian and thus the temperature of the atomic ensemble may not be well defined. The achievable kinetic energy is so small that the cooled atoms are trapped in the vicinity of the laser field nodes. An explanation for these effects is given in terms of Sisyphus cooling.

Annual Meeting Optical Society of America•Jan 1, 1991•0 citations

New type of sub-Doppler laser cooling for three-level atoms

Dmitry V. Kosachiov, Yuri V. Rozhdestvenskii

We examine the laser cooling of three-level (Lambda) -atoms in the field of two standing waves when frequency detunings are considerably greater than natural width of the excited state as well as the Rabi frequencies in the system. It is shown that at the difference of frequency detunings is small when compared to the Rabi frequencies sub-Doppler cooling of the (Lambda) -atom is possible. We present the dependence of the light pressure force on the atoms velocity and dependence of cooled atoms temperature on the parameters of the exciting waves.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 6, 1996•0 citations
Theoretical analysis of sub-Doppler laser cooling of 24Mg atoms using 33 P2 → 33 D3 transition in the field of two counterpropagating light waves with opposite circular polarizations is presented. The standard semi-classical approach based on the Fokker-Plank equation is exploited for numerical modeling of laser cooling. The problem is solved out of limits of slow atom approximation and for arbitrary light intensity. The dependences of light force and diffusion on an atomic velocity are studied for various frequency detuning and Rabi frequency. Also, to obtain optimal parameters of laser cooling, the atomic velocity distributions are investigated for various conditions and the dependence of average atomic kinetic energy on the light field intensity and frequency detuning is calculated. In the case of strong field a multi-spike velocity distribution profile is observed. It results from various nonlinear effects accompany absorption of laser photons by atoms. In conclusion we make additional recommendations to increase atoms in metastable state 33 P2, what is necessary for effective laser cooling
We present the theoretical analysis of sub-Doppler laser cooling of 24Mg atoms using dipole transition 33P2→33D3 under two counterpropagating light waves with opposite circular polarizations (one-dimensional σ+σ– configuration). For numerical calculations the standard semi-classical approach based on the Fokker–Planck equation for linear momentum distribution of atoms is exploited. The distributions are gained beyond the limits of slow atoms approximation and for an arbitrary light field intensity. The absence of these limits allows us to determine the optimal parameters of the light field to maximize a fraction of ultracold atoms (T ~ 10 μK) in a whole atomic cloud. In particular, under certain conditions the fraction can reach a value of 50%. Solution of the existing problems in deep laser cooling of magnesium atoms has obvious prospects for atomic optics and quantum metrology: for instance, in designing new-generation optical frequency and time standards based on cold atoms in optical lattices.
Deep laser cooling of 24Mg^{24}\mathrm{Mg}24Mg atoms has been theoretically studied. We propose a two-stage sub-Doppler cooling strategy using electrodipole transition $3\phantom{\rule{0.16em}{0ex}}{}^{3}{P}_{2}\ensuremath{\rightarrow}3\phantom{\rule{0.16em}{0ex}}{}^{3}{D}_{3}$ ($\ensuremath{\lambda}\phantom{\rule{0.16em}{0ex}}=\phantom{\rule{0.16em}{0ex}}383.8$ nm). The first stage implies exploiting magneto-optical trap with ${\ensuremath{\sigma}}^{+}$ and ${\ensuremath{\sigma}}^{\ensuremath{-}}$ light beams, while at the second stage lin $\ensuremath{\perp}$ lin molasses is used. We focus on achieving a large number of ultracold atoms (${T}_{\mathrm{eff}}<10 \ensuremath{\mu}\mathrm{K}$) in a cold-atomic cloud. The calculations have been based on quantum treatment, taking into full account the recoil effect and beyond many widely used approximations. Steady-state values of average kinetic energy and linear momentum distributions of cold atoms have been analyzed for various light-field intensities and frequency detunings. The results of conducted quantum analysis have been significantly different from the results achieved under a semiclassical approximation based on the Fokker-Planck equation. The second cooling stage allows achieving sufficiently lower kinetic energies of the atomic cloud as well as increased fraction of ultracold atoms at certain conditions compared to the first one. We hope that the obtained results can help in overcoming current experimental problems in deep cooling of 24Mg^{24}\mathrm{Mg}24Mg atoms by means of laser field. Cold magnesium atoms cooled in a large amount to several $\ensuremath{\mu}\mathrm{K}$ are of huge interest to, for example, quantum metrology and to other many-body cold-atoms physics.
Laser cooling dynamics of neutral atoms with a closed optical transition Jg → Je in light fields with nonuniform polarization formed by counterpropagating waves with linear, circular or elliptical polarization was considered. For the case of finite interaction time of atoms with light field both mechanisms of Doppler and Sub-Doppler laser cooling affected on atoms in ensemble having different velocities were taken into account. We get qualitative relations on a base of numerical analysis in a frame of quasiclassical treatment of laser cooling. These relations allow to define optimal parameters of cooling waves, i.e. polarization, detuning from atomic resonance and intensity of light waves for the most rapid and dip laser cooling from initially wide momentum distribution for finite interaction time of atoms with laser field
In sub-Doppler laser cooling of atoms, the lowest temperatures are known to occur at low (but not too low) excitation, and the temperature increases roughly linearly with laser intensity. However, under conditions for which the lowest temperatures are obtained, the small velocity capture range and low optical pumping rate limit the number of atoms that can be collected into the cold sample. In this study, we present measurements for laser cooling of Rb and metastable He atoms for two counterpropagating laser beams with orthogonal linear polarization (lin\ensuremath{\perp}lin) over a wide range of saturation parameters and laser detunings, together with results of semiclassical (Fokker-Planck) and quantum density matrix calculations. We find that at higher laser intensity, a larger number of atoms can be collected into a final velocity distribution that is significantly narrower than that given by a linear extrapolation vs the square root of laser intensity. Two cooling mechanisms are at work: the sub-Doppler Sisyphus mechanism and also Doppler cooling. Under certain conditions that we discuss, Doppler cooling aids Sisyphus cooling by collecting high-velocity atoms beyond the Sisyphus capture range. He∗{\mathrm{He}}^{*}He∗ presents a rather unusual situation in that the minimum average kinetic energy (Eav){(E}_{\mathrm{av}})(Eav​) for purely Sisyphus cooling is comparable to the minimum value of Eav{E}_{\mathrm{av}}Eav​ with Doppler cooling alone.
A theoretical analysis is given for 1-D laser cooling below the Doppler limit of J = 1/2 ground- state atoms. The laser field consists of a pair of counterpropagating, linearly polarized low- power beams, whose polarization directions differ by an angle θ (0 ≤ θ ≤ π/2). For θ ≪ 1, the effective optical pumping time is shown to increase strongly near the nodes of the standing wave and the cooling force can be much larger than that for θ ~1. Moreover, for θ ≪ 1, it can be shown that the stimulated part of the atomic diffusion is reduced considerably as compared with that for θ ~ 1. As a consequence it is possible to achieve an equilibrium atomic distribution that, for θ ≪ 1, is characterized by a mean kinetic energy lower than that predicted to occur for θ = π/2. The equilibrium velocity distribution is not necessarily Maxwellian and thus the temperature of the atomic ensemble may not be well defined. The achievable kinetic energy is so small that the cooled atoms are trapped in the vicinity of the laser field nodes. An explanation for these effects is given in terms of Sisyphus cooling.
We examine the laser cooling of three-level (Lambda) -atoms in the field of two standing waves when frequency detunings are considerably greater than natural width of the excited state as well as the Rabi frequencies in the system. It is shown that at the difference of frequency detunings is small when compared to the Rabi frequencies sub-Doppler cooling of the (Lambda) -atom is possible. We present the dependence of the light pressure force on the atoms velocity and dependence of cooled atoms temperature on the parameters of the exciting waves.