Abstract We derive the semiclassical evolution equations for a system consisting of helium-3 atoms in the 2 3 S metastable state interacting with a light field far-detuned from the 2 3 S − 2 3 P transition, in the presence of metastability exchange collisions with ground state helium atoms and a static magnetic field. For two configurations, each corresponding to a particular choice of atom–light detuning in which the contribution of either the metastable level F = 1 / 2 or F = 3 / 2 is dominant, we derive a simple model of three coupled collective spins from which we can analytically extract an effective coupling constant between the collective nuclear spin and light. In these two configurations, we compare the predictions of our simplified model with the full model.Abstract We derive the semiclassical evolution equations for a system consisting of helium-3 atoms in the 2 3 S metastable state interacting with a light field far-detuned from the 2 3 S − 2 3 P transition, in the presence of metastability exchange collisions with ground state helium atoms and a static magnetic field. For two configurations, each corresponding to a particular choice of atom–light detuning in which the contribution of either the metastable level F = 1 / 2 or F = 3 / 2 is dominant, we derive a simple model of three coupled collective spins from which we can analytically extract an effective coupling constant between the collective nuclear spin and light. In these two configurations, we compare the predictions of our simplified model with the full model.

arXiv:2406.11790New Journal of PhysicsOct 1, 20242 citations

Atom–Field Interaction: Semiclassical Approach

Miguel Orszag

Springer eBooksJan 1, 20240 citations

Atom–Field Interaction: Semiclassical Approach

Springer eBooksOct 22, 20070 citations

Quantum-electrodynamic calculation of hyperfine-state populations in atomic sodium

Peter M. Farrell, W. R. MacGillivray, M. C. Standage

A quantum-electrodynamic (QED) description of the resonant interaction of monochromatic light with the ${3}^{2}$ ${\mathit{S}}_{1/2}$ (F'=2)\ensuremath{\rightarrow} ${3}^{2}$ ${\mathit{P}}_{3/2}$ (F=3,2,1) hyperfine transitions of the sodium ${D}_{2}$ line is formulated in terms of the Heisenberg atomic operator. Off-diagonal state coherences and all relaxation terms are included. It is found that the equations for the populations, optical coherences, and certain state coherences form a closed subset of the total system of equations. This subset is small enough to be computed numerically. The results of calculations with this model are compared with three previously developed semiclassical descriptions using the density operator. One of the semiclassical models was developed to describe the interaction of weak light with the atomic transition while another is suitable in the case of high-intensity light. For both \ensuremath{\pi} and \ensuremath{\sigma} excitation it is shown that the QED calculated values for the time-averaged, excited-level population probability converge to those of each of the semiclassical models in the appropriate limit of light intensity. For homogeneous broadening, results show that the optimum light intensity to obtain the largest fraction of atoms in the ${3}^{2}$ ${P}_{3/2}$ level after transversing a 1-mm-diam laser beam is 1.15 mW/ ${\mathrm{mm}}^{2}$ for \ensuremath{\pi} excitation and 1.43 mW/ ${\mathrm{mm}}^{2}$ for \ensuremath{\sigma} excitation.A quantum-electrodynamic (QED) description of the resonant interaction of monochromatic light with the ${3}^{2}$${\mathit{S}}_{1/2}$(F'=2)\ensuremath{\rightarrow}${3}^{2}$${\mathit{P}}_{3/2}$(F=3,2,1) hyperfine transitions of the sodium ${D}_{2}$ line is formulated in terms of the Heisenberg atomic operator. Off-diagonal state coherences and all relaxation terms are included. It is found that the equations for the populations, optical coherences, and certain state coherences form a closed subset of the total system of equations. This subset is small enough to be computed numerically. The results of calculations with this model are compared with three previously developed semiclassical descriptions using the density operator. One of the semiclassical models was developed to describe the interaction of weak light with the atomic transition while another is suitable in the case of high-intensity light. For both \ensuremath{\pi} and \ensuremath{\sigma} excitation it is shown that the QED calculated values for the time-averaged, excited-level population probability converge to those of each of the semiclassical models in the appropriate limit of light intensity. For homogeneous broadening, results show that the optimum light intensity to obtain the largest fraction of atoms in the ${3}^{2}$${P}_{3/2}$ level after transversing a 1-mm-diam laser beam is 1.15 mW/${\mathrm{mm}}^{2}$ for \ensuremath{\pi} excitation and 1.43 mW/${\mathrm{mm}}^{2}$ for \ensuremath{\sigma} excitation.

Physical Review AJun 1, 198858 citations

Atom-Field Interaction: Semiclassical Approach

Miguel Orszag

Springer eBooksJan 1, 20000 citations

Itô – Stratonovich dilemma in the problem of laser cooling of atoms: limits of applicability of the semiclassical approximation

Anastasia Kirpichnikova, Прудников Олег Николаевич, А. В. Тайченачев +1 more

Abstract We report a comparative analysis of the limits of laser cooling of atoms in light fields both on the basis of a numerical solution of the quantum kinetic equation for the atomic density matrix, which makes it possible to accurately take into account quantum recoil effects during the interaction of atoms with field photons, and within the framework of the semiclassical approach using various forms of the Fokker – Plank equation. The analysis allows one to outline the limits of applicability of the semiclassical approach, as well as to choose an unambiguous form for introducing the diffusion contribution to the Fokker – Planck equation in the semiclassical description of atomic kinetics.Abstract We report a comparative analysis of the limits of laser cooling of atoms in light fields both on the basis of a numerical solution of the quantum kinetic equation for the atomic density matrix, which makes it possible to accurately take into account quantum recoil effects during the interaction of atoms with field photons, and within the framework of the semiclassical approach using various forms of the Fokker – Plank equation. The analysis allows one to outline the limits of applicability of the semiclassical approach, as well as to choose an unambiguous form for introducing the diffusion contribution to the Fokker – Planck equation in the semiclassical description of atomic kinetics.

Quantum ElectronicsFeb 1, 20224 citations

A quantum-electrodynamic (QED) description of the resonant interaction of monochromatic light with the

{3}^{2}

{\mathit{S}}_{1/2}

(F'=2)\ensuremath{\rightarrow}

{3}^{2}

{\mathit{P}}_{3/2}

(F=3,2,1) hyperfine transitions of the sodium

{D}_{2}

line is formulated in terms of the Heisenberg atomic operator. Off-diagonal state coherences and all relaxation terms are included. It is found that the equations for the populations, optical coherences, and certain state coherences form a closed subset of the total system of equations. This subset is small enough to be computed numerically. The results of calculations with this model are compared with three previously developed semiclassical descriptions using the density operator. One of the semiclassical models was developed to describe the interaction of weak light with the atomic transition while another is suitable in the case of high-intensity light. For both \ensuremath{\pi} and \ensuremath{\sigma} excitation it is shown that the QED calculated values for the time-averaged, excited-level population probability converge to those of each of the semiclassical models in the appropriate limit of light intensity. For homogeneous broadening, results show that the optimum light intensity to obtain the largest fraction of atoms in the

{3}^{2}

{P}_{3/2}

level after transversing a 1-mm-diam laser beam is 1.15 mW/

{\mathrm{mm}}^{2}

for \ensuremath{\pi} excitation and 1.43 mW/

{\mathrm{mm}}^{2}

for \ensuremath{\sigma} excitation.