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

arXiv:1306.0048 · Physical Review A

Hyperfine-frequency shifts of alkali-metal atoms during long-range collisions

B. H. McGuyer

Published May 31, 2013• 6 citations
arXivHTMLPDF

Abstract

Collisions with chemically inert atoms or molecules change the hyperfine coupling $A\phantom{\rule{0.16em}{0ex}}\mathbf{I}\ifmmode\cdot\else\textperiodcentered\fi{}\mathbf{S}$ of an alkali-metal atom through the hyperfine-shift interaction $\ensuremath{\delta}A\phantom{\rule{0.16em}{0ex}}\mathbf{I}\ifmmode\cdot\else\textperiodcentered\fi{}\mathbf{S}$. This interaction is responsible for the pressure shifts of the microwave resonances of alkali-metal atoms in buffer gases, is an important spin interaction in alkali-metal--noble-gas van der Waals molecules, and is anticipated to enable the magnetoassociation of ultracold molecules such as RbSr. An improved estimate is presented for the long-range asymptote of this interaction for Na, K, Rb, and Cs. To test the results, the change in hyperfine coupling due to a static electric field is estimated and reasonable agreement is found.

DOI
10.1103/physreva.87.054702

Related papers

Pseudopotential analysis on hyperfine splitting frequency shift of alkali-metal atoms in noble gases, revisited

Kiyoshi Ishikawa

Theoretical pseudopotentials and dispersion potentials are used to study ground-state hyperfine splitting frequencies of alkali-metal atoms (Li, Na, K, Rb, and Cs) in noble gases (He, Ne, Ar, Kr, and Xe) in all combinations. With a single fitting parameter, calculations based on first-order perturbation theory qualitatively present each temperature dependence of the measured frequency shift. With this parameter and excitation energies of alkali-metal and noble-gas atoms, the hyperfine splitting frequency of alkali-metal atoms is suitable for investigating the properties of noble-gas atoms, such as the s-wave scattering length of electrons, the electric-dipole polarizability, and the van der Waals radius. This study suggests the possibility of improving excitation energies and van der Waals potentials of colliding pairs.

The Journal of Chemical Physics•Feb 9, 2023•4 citations

Ultracold atom-molecule collisions with hyperfine coupling

Andrea Simoni, J. M. Launay

We study atom-molecule inelastic scattering in a trapped alkali metal gas at ultracold temperature. We derive the atom-molecule Hamiltonian in the presence of hyperfine interactions and introduce angular momentum coupling schemes suited to the description of the short-and long-range physics of the collision. We provide a first estimate of the relative importance of rotational, hyperfine-changing, and spin-changing transitions within a simple rigid-rotor model. We also investigate the occurrence of resonance phenomena near the atom-molecule energy threshold.

Laser Physics•Apr 1, 2006•12 citations

Estimates of spin-exchange parameters for alkali-metal–noble-gas pairs

Thad G Walker

Estimates of frequency-shift enhancement factors, binary cross sections for spin exchange and spin relaxation, chemical equilibrium constants, and spin-exchange and spin-rotation interactions in van der Waals molecules are presented for alkali-metal atoms interacting with noble-gas atoms. These results are compared to experiments and are also presented for those pairs which have not been studied experimentally.

Physical Review A•Nov 1, 1989•93 citations

Frequency shifts of the magnetic-resonance spectrum of mixtures of nuclear spin-polarized noble gases and vapors of spin-polarized alkali-metal atoms

S. R. Schaefer, G. D. Cates, Ting-Ray Chien +3 more

We report the first quantitative theoretical and experimental studies of frequency shifts of nuclear-magnetic-resonance (NMR) lines of noble-gas atoms and the corresponding frequency shifts of electron-paramagnetic-resonance (EPR) lines of alkali-metal atoms in mixtures of nuclear spin-polarized noble gases and vapors of spin-polarized alkali-metal atoms. The shifts are primarily due to the Fermi-contact hyperfine interaction. For the heavier noble gases there can be relatively large (\ensuremath{\approxeq}10%) contributions to the shifts from van der Waals molecules. The NMR frequencies of polarized $^{83}\mathrm{Kr}$ and $^{129}\mathrm{Xe}$ were measured in a vapor of spin-polarized alkali-metal atoms oriented parallel and antiparallel to the external magnetic field. The shift in the EPR frequency of the alkali-metal vapor due to the polarized noble-gas nuclei was measured simultaneously, thus providing a measurement of the absolute noble-gas nuclear polarization. The frequency shifts can be used as a convenient way to measure the absolute nuclear spin polarization of noble gases.

Physical Review A•Jun 1, 1989•155 citations

Polarization of the nuclear spins of noble-gas atoms by spin exchange with optically pumped alkali-metal atoms

W. Happer, E. Miron, S. Schaefer +3 more

The theory of spin exchange between optically pumped alkali-metal atoms and noble-gas nuclei is presented. Spin exchange with heavy noble gases is dominated by interactions in long-lived van der Waals molecules. The main spin interactions are assumed to be the spin-rotation interactions $\ensuremath{\gamma}\stackrel{\ensuremath{\rightarrow}}{\mathrm{N}}\ifmmode\cdot\else\textperiodcentered\fi{}\stackrel{\ensuremath{\rightarrow}}{\mathrm{S}}$ between the rotational angular momentum $\stackrel{\ensuremath{\rightarrow}}{\mathrm{N}}$ of the alkali-metal---noble-gas pair and the electron spin $\stackrel{\ensuremath{\rightarrow}}{\mathrm{S}}$ of the alkali-metal atom, and the contact hyperfine interaction $\ensuremath{\alpha}\stackrel{\ensuremath{\rightarrow}}{\mathrm{K}}\ifmmode\cdot\else\textperiodcentered\fi{}\stackrel{\ensuremath{\rightarrow}}{\mathrm{S}}$ between the nuclear spin $\stackrel{\ensuremath{\rightarrow}}{\mathrm{K}}$ of the noble-gas atom and the electron spin $\stackrel{\ensuremath{\rightarrow}}{\mathrm{S}}$. Arbitrary values for $K$ and for the nuclear spin $I$ of the alkali-metal atom are assumed. Precise formal expressions for spin transfer coefficients are given along with convenient approximations based on a perturbation expansion in powers of ${(\frac{\ensuremath{\alpha}}{\ensuremath{\gamma}N})}^{2}$, a quantity which has been shown to be small by experiment.

Physical Review A•Jun 1, 1984•468 citations

Alkali-Metal Hyperfine Shift in the Van der Waals Molecule KAr

Richard R. Freeman, Edward M. Mattison, David E. Pritchard +1 more

The hyperfine interaction of K in KAr has been measured in several vibrational states of KAr. The results yield a value for the hyperfine shift $\ensuremath{\alpha}$ as a function of internuclear separation $R$ given by $\ensuremath{\alpha}=\ensuremath{-}115(R\ensuremath{-}{R}_{0})$ kHz, where $R$ is in bohrs and ${R}_{0}=12.0$ bohr, valid over the range $10.25 \mathrm{bohr}<R<12.0 \mathrm{bohr}$.

Physical Review Letters•Aug 12, 1974•19 citations
Collisions with chemically inert atoms or molecules change the hyperfine coupling AI\ifmmode⋅\else\textperiodcentered\fiSA\phantom{\rule{0.16em}{0ex}}\mathbf{I}\ifmmode\cdot\else\textperiodcentered\fi{}\mathbf{S}AI\ifmmode⋅\else\textperiodcentered\fiS of an alkali-metal atom through the hyperfine-shift interaction \ensuremathδAI\ifmmode⋅\else\textperiodcentered\fiS\ensuremath{\delta}A\phantom{\rule{0.16em}{0ex}}\mathbf{I}\ifmmode\cdot\else\textperiodcentered\fi{}\mathbf{S}\ensuremathδAI\ifmmode⋅\else\textperiodcentered\fiS. This interaction is responsible for the pressure shifts of the microwave resonances of alkali-metal atoms in buffer gases, is an important spin interaction in alkali-metal--noble-gas van der Waals molecules, and is anticipated to enable the magnetoassociation of ultracold molecules such as RbSr. An improved estimate is presented for the long-range asymptote of this interaction for Na, K, Rb, and Cs. To test the results, the change in hyperfine coupling due to a static electric field is estimated and reasonable agreement is found.
Theoretical pseudopotentials and dispersion potentials are used to study ground-state hyperfine splitting frequencies of alkali-metal atoms (Li, Na, K, Rb, and Cs) in noble gases (He, Ne, Ar, Kr, and Xe) in all combinations. With a single fitting parameter, calculations based on first-order perturbation theory qualitatively present each temperature dependence of the measured frequency shift. With this parameter and excitation energies of alkali-metal and noble-gas atoms, the hyperfine splitting frequency of alkali-metal atoms is suitable for investigating the properties of noble-gas atoms, such as the s-wave scattering length of electrons, the electric-dipole polarizability, and the van der Waals radius. This study suggests the possibility of improving excitation energies and van der Waals potentials of colliding pairs.
We study atom-molecule inelastic scattering in a trapped alkali metal gas at ultracold temperature. We derive the atom-molecule Hamiltonian in the presence of hyperfine interactions and introduce angular momentum coupling schemes suited to the description of the short-and long-range physics of the collision. We provide a first estimate of the relative importance of rotational, hyperfine-changing, and spin-changing transitions within a simple rigid-rotor model. We also investigate the occurrence of resonance phenomena near the atom-molecule energy threshold.
We report the first quantitative theoretical and experimental studies of frequency shifts of nuclear-magnetic-resonance (NMR) lines of noble-gas atoms and the corresponding frequency shifts of electron-paramagnetic-resonance (EPR) lines of alkali-metal atoms in mixtures of nuclear spin-polarized noble gases and vapors of spin-polarized alkali-metal atoms. The shifts are primarily due to the Fermi-contact hyperfine interaction. For the heavier noble gases there can be relatively large (\ensuremath{\approxeq}10%) contributions to the shifts from van der Waals molecules. The NMR frequencies of polarized 83Kr^{83}\mathrm{Kr}83Kr and 129Xe^{129}\mathrm{Xe}129Xe were measured in a vapor of spin-polarized alkali-metal atoms oriented parallel and antiparallel to the external magnetic field. The shift in the EPR frequency of the alkali-metal vapor due to the polarized noble-gas nuclei was measured simultaneously, thus providing a measurement of the absolute noble-gas nuclear polarization. The frequency shifts can be used as a convenient way to measure the absolute nuclear spin polarization of noble gases.
The theory of spin exchange between optically pumped alkali-metal atoms and noble-gas nuclei is presented. Spin exchange with heavy noble gases is dominated by interactions in long-lived van der Waals molecules. The main spin interactions are assumed to be the spin-rotation interactions $\ensuremath{\gamma}\stackrel{\ensuremath{\rightarrow}}{\mathrm{N}}\ifmmode\cdot\else\textperiodcentered\fi{}\stackrel{\ensuremath{\rightarrow}}{\mathrm{S}}$ between the rotational angular momentum $\stackrel{\ensuremath{\rightarrow}}{\mathrm{N}}$ of the alkali-metal---noble-gas pair and the electron spin $\stackrel{\ensuremath{\rightarrow}}{\mathrm{S}}$ of the alkali-metal atom, and the contact hyperfine interaction $\ensuremath{\alpha}\stackrel{\ensuremath{\rightarrow}}{\mathrm{K}}\ifmmode\cdot\else\textperiodcentered\fi{}\stackrel{\ensuremath{\rightarrow}}{\mathrm{S}}$ between the nuclear spin $\stackrel{\ensuremath{\rightarrow}}{\mathrm{K}}$ of the noble-gas atom and the electron spin $\stackrel{\ensuremath{\rightarrow}}{\mathrm{S}}$. Arbitrary values for KKK and for the nuclear spin III of the alkali-metal atom are assumed. Precise formal expressions for spin transfer coefficients are given along with convenient approximations based on a perturbation expansion in powers of ${(\frac{\ensuremath{\alpha}}{\ensuremath{\gamma}N})}^{2}$, a quantity which has been shown to be small by experiment.
The hyperfine interaction of K in KAr has been measured in several vibrational states of KAr. The results yield a value for the hyperfine shift $\ensuremath{\alpha}$ as a function of internuclear separation RRR given by $\ensuremath{\alpha}=\ensuremath{-}115(R\ensuremath{-}{R}_{0})$ kHz, where RRR is in bohrs and R0=12.0{R}_{0}=12.0R0​=12.0 bohr, valid over the range 10.25bohr<R<12.0bohr10.25 \mathrm{bohr}<R<12.0 \mathrm{bohr}10.25bohr<R<12.0bohr.