A Theoretical Model for the Interaction between Excited and Ground State Atoms. Application to Pressure Broadening

An exact quantum adiabatic evaluation of the shift of an isolated spectral line is applied to the potassium 7s-4p transition perturbed by argon. The long-range interaction of excited alkali states with noble gases is computed with a large basis set of unperturbed atomic states, a multipole interaction and a pseudopotential to compare with a measurement of the dependence of the shift on temperature. The parameters of the theoretical potassium-argon excited-state potential are determined by adjusting the theoretical temperature dependence to fit the observations. Previous pseudopotential models, fitted to ground-state interactions derived from scattering experiments, show weaker long-range interactions than the authors find. The conclusions are consistent with independent line wing experiments on this and other alkali-noble-gas systems that reveal significant interactions at long range.An exact quantum adiabatic evaluation of the shift of an isolated spectral line is applied to the potassium 7s-4p transition perturbed by argon. The long-range interaction of excited alkali states with noble gases is computed with a large basis set of unperturbed atomic states, a multipole interaction and a pseudopotential to compare with a measurement of the dependence of the shift on temperature. The parameters of the theoretical potassium-argon excited-state potential are determined by adjusting the theoretical temperature dependence to fit the observations. Previous pseudopotential models, fitted to ground-state interactions derived from scattering experiments, show weaker long-range interactions than the authors find. The conclusions are consistent with independent line wing experiments on this and other alkali-noble-gas systems that reveal significant interactions at long range.

Journal of Physics B Atomic Molecular and Optical PhysicsJan 14, 19913 citations

Pressure Shifts of Highly Excited States of Atoms

Marvin H. Mittleman

Physical ReviewFeb 5, 19681 citation

Optical pumping of alkali-metal vapor in the quasi-high-pressure regime

Kezheng Yan, Jinbo Hu, Nan Zhao

Optical pumping is fundamental to high-precision measurement using thermal alkali-metal atoms in vapor cells. In applications such as atomic magnetometry, buffer gases (e.g., $\mathrm{N}_2$ or $\mathrm{He}$ ) at specific pressures are introduced to quench fluorescence and mitigate wall relaxation. In the high-pressure limit (e.g., the $\mathrm{N}_2$ pressure $p_{\mathrm{N}_2}> 1$ ~atm), where collisional broadening exceeds hyperfine splittings of the atoms, optical pumping theory provides a clear description of the angular momentum exchange between photons and atomic spins. However, in many magnetic sensing scenarios, the high-pressure approximation becomes inadequate as its pressure conditions are not strictly satisfied. Consequently, an explicit description of optical pumping under realistic pressures is critical for selecting operating points and enhancing system performance. To address this, we develop a unified theoretical framework of optical pumping in the quasi-high-pressure regime, where collisional broadening is comparable to the ground-state hyperfine splitting. We demonstrate that light absorption, spin polarization, and magnetic-resonance linewidth in this regime differ significantly from those predicted by the high-pressure limit and offer favorable operating conditions. Our study extends conventional modeling and offers critical guidance for atomic magnetometry operating under realistic buffer gas pressures.Optical pumping is fundamental to high-precision measurement using thermal alkali-metal atoms in vapor cells. In applications such as atomic magnetometry, buffer gases (e.g., $\mathrm{N}_2$ or $\mathrm{He}$) at specific pressures are introduced to quench fluorescence and mitigate wall relaxation. In the high-pressure limit (e.g., the $\mathrm{N}_2$ pressure $p_{\mathrm{N}_2}> 1$~atm), where collisional broadening exceeds hyperfine splittings of the atoms, optical pumping theory provides a clear description of the angular momentum exchange between photons and atomic spins. However, in many magnetic sensing scenarios, the high-pressure approximation becomes inadequate as its pressure conditions are not strictly satisfied. Consequently, an explicit description of optical pumping under realistic pressures is critical for selecting operating points and enhancing system performance. To address this, we develop a unified theoretical framework of optical pumping in the quasi-high-pressure regime, where collisional broadening is comparable to the ground-state hyperfine splitting. We demonstrate that light absorption, spin polarization, and magnetic-resonance linewidth in this regime differ significantly from those predicted by the high-pressure limit and offer favorable operating conditions. Our study extends conventional modeling and offers critical guidance for atomic magnetometry operating under realistic buffer gas pressures.

physics.atom-phCross-listedarXiv:2603.05859Physical Review AMar 9, 20260 citations

Theory of the condensed state in a system of excited atoms

Edward A. Manykin, M. I. Ozhovan, Pavel P. Poluektov

Journal of Experimental and Theoretical PhysicsFeb 1, 19836 citations

Pressure shift and broadening of the resonance line of barium atoms in liquid helium

S. I. Kanorsky, Markus Arndt, R. Dziewior +2 more

We have measured the pressure broadening and shift of the excitation and emission lines of the 6 ${\mathit{s}}^{2}$ $^{1}$ ${\mathit{S}}_{0}$ \ensuremath{\rightarrow}6s6p $^{1}$ ${\mathit{P}}_{1}$ transition of Ba atoms implanted in liquid and solid helium at 1.5 K. The observed spectra are quantitatively explained within the adiabatic line-broadening theory by assuming a bubble structure of the trapping sites for the Ba atoms. The evolution of the bubble shape and size in the optical excitation-deexcitation cycle is modeled theoretically.We have measured the pressure broadening and shift of the excitation and emission lines of the 6${\mathit{s}}^{2}$ $^{1}$${\mathit{S}}_{0}$\ensuremath{\rightarrow}6s6p $^{1}$${\mathit{P}}_{1}$ transition of Ba atoms implanted in liquid and solid helium at 1.5 K. The observed spectra are quantitatively explained within the adiabatic line-broadening theory by assuming a bubble structure of the trapping sites for the Ba atoms. The evolution of the bubble shape and size in the optical excitation-deexcitation cycle is modeled theoretically.

Physical review. B, Condensed matterSep 1, 199474 citations

Resonance interaction between one excited and one ground state atom

M. Boström, Jevon J. Longdell, D.J. Mitchell +1 more

The European Physical Journal DJan 1, 200330 citations

Optical pumping is fundamental to high-precision measurement using thermal alkali-metal atoms in vapor cells. In applications such as atomic magnetometry, buffer gases (e.g.,

\mathrm{N}_2

\mathrm{He}

) at specific pressures are introduced to quench fluorescence and mitigate wall relaxation. In the high-pressure limit (e.g., the

\mathrm{N}_2

pressure

p_{\mathrm{N}_2}> 1

~atm), where collisional broadening exceeds hyperfine splittings of the atoms, optical pumping theory provides a clear description of the angular momentum exchange between photons and atomic spins. However, in many magnetic sensing scenarios, the high-pressure approximation becomes inadequate as its pressure conditions are not strictly satisfied. Consequently, an explicit description of optical pumping under realistic pressures is critical for selecting operating points and enhancing system performance. To address this, we develop a unified theoretical framework of optical pumping in the quasi-high-pressure regime, where collisional broadening is comparable to the ground-state hyperfine splitting. We demonstrate that light absorption, spin polarization, and magnetic-resonance linewidth in this regime differ significantly from those predicted by the high-pressure limit and offer favorable operating conditions. Our study extends conventional modeling and offers critical guidance for atomic magnetometry operating under realistic buffer gas pressures.

We have measured the pressure broadening and shift of the excitation and emission lines of the 6

{\mathit{s}}^{2}

^{1}

{\mathit{S}}_{0}

\ensuremath{\rightarrow}6s6p

^{1}

{\mathit{P}}_{1}

transition of Ba atoms implanted in liquid and solid helium at 1.5 K. The observed spectra are quantitatively explained within the adiabatic line-broadening theory by assuming a bubble structure of the trapping sites for the Ba atoms. The evolution of the bubble shape and size in the optical excitation-deexcitation cycle is modeled theoretically.