Physical review. B, Condensed matter

Optical pumping and optical detection of the magnetic resonance of alkali-metal atoms in superfluid helium

Toshiya Kinoshita, Yoshiro Takahashi, T. Yabuzaki

Published Feb 1, 1994• 57 citations

Abstract

By ${\mathit{D}}_{1}$-line optical pumping of alkali-metal atoms (Cs and Rb) in superfluid helium (He II), we could achieve large spin polarization of the atoms in the ground states, more than 50% for both electron and nuclear spins, especially for the Cs atoms. The alkali-metal atoms were implanted into He II by laser sputtering. We detected optically the magnetic resonances between the ground-state Zeeman sublevels, and found that the g values and hyperfine constants in He II were the same as in vacuum within the experimental error. We discuss possible applications of these spin-polarized atoms in He II.

DOI: 10.1103/physrevb.49.3648

Related papers

Optical Methods of Atomic Orientation and of Magnetic Resonance*

Alfred Kastler

Journal of the Optical Society of AmericaJun 1, 1957223 citations

Observation of polarized alkali atoms in experiments on optical orientation in a He–Rb and He-Cs mixture under conditions of a pulsed gas discharge

Sergei P. Dmitriev, N. A. Dovator, Victor A. Kartoshkin +1 more

Journal of Physics Conference SeriesDec 1, 20181 citation

Laser–radio-frequency double-resonance spectroscopy of 84−87Rb isotopes trapped in superfluid helium

X. F. Yang, T. Furukawa, T. Wakui +25 more

Physical Review ANov 19, 20149 citations

Spin polarization of 85Rb atoms in collisions with optically oriented metastable 4He atoms in alkali–helium plasma

Sergei P. Dmitriev, N. A. Dovator, Victor A. Kartoshkin

Technical Physics LettersJan 1, 20166 citations

Optical properties of alkali-metal atoms in pressurized liquid helium

Toshiya Kinoshita, K. Fukuda, Yoshiro Takahashi +1 more

Physical Review AOct 1, 199571 citations

Optical Detection of Nonradiating Alkali Atoms in Solid Helium

T. Eichler, R. Müller-Siebert, Daniel Nettels +2 more

Physical Review LettersMar 7, 200219 citations

Physical review. B, Condensed matter

Optical pumping and optical detection of the magnetic resonance of alkali-metal atoms in superfluid helium

Toshiya Kinoshita, Yoshiro Takahashi, T. Yabuzaki

Published Feb 1, 1994• 57 citations

Publisher

Abstract

{\mathit{D}}_{1}

-line optical pumping of alkali-metal atoms (Cs and Rb) in superfluid helium (He II), we could achieve large spin polarization of the atoms in the ground states, more than 50% for both electron and nuclear spins, especially for the Cs atoms. The alkali-metal atoms were implanted into He II by laser sputtering. We detected optically the magnetic resonances between the ground-state Zeeman sublevels, and found that the g values and hyperfine constants in He II were the same as in vacuum within the experimental error. We discuss possible applications of these spin-polarized atoms in He II.

DOI: 10.1103/physrevb.49.3648

Related papers

Optical Methods of Atomic Orientation and of Magnetic Resonance*

Alfred Kastler

In the optical excitation of atoms with polarized light, producing excited atoms, only some of the Zeeman sublevels of the excited state are actually reached, so that large differences of population can be built up between Zeeman sublevels or between hyperfine structure (hfs) levels. This property can be used to detect radio-frequency resonance in optically excited atomic states. These resonances produce a characteristic change in intensity or in the degree of polarization of the light re-emitted. Zeeman intervals, Stark effects, and hfs intervals can be measured in this manner. (The Stark constant of the 63P1 level of Hg and the electric quadrupole moments of the alkali atoms have been obtained in this way.)The technique of “optical pumping” gives a way to concentrate atoms in some of the Zeeman sublevels of one of the hfs levels of the ground state.Atomic orientation has been obtained with the Na atom, in an atomic beam and in the vapor in equilibrium with the metal. The orientation effects have been studied by detection of radio-frequency resonance signals in the ground state. Orientation can be increased many times by adding a variable pressure of a foreign gas to the pure Na vapor. Because of the coupling between nuclear spin and electron spin, nuclear orientation is produced at the same time as atomic orientation.In the optical excitation of atoms with polarized light, producing excited atoms, only some of the Zeeman sublevels of the excited state are actually reached, so that large differences of population can be built up between Zeeman sublevels or between hyperfine structure (hfs) levels. This property can be used to detect radio-frequency resonance in optically excited atomic states. These resonances produce a characteristic change in intensity or in the degree of polarization of the light re-emitted. Zeeman intervals, Stark effects, and hfs intervals can be measured in this manner. (The Stark constant of the 63P1 level of Hg and the electric quadrupole moments of the alkali atoms have been obtained in this way.)The technique of “optical pumping” gives a way to concentrate atoms in some of the Zeeman sublevels of one of the hfs levels of the ground state.Atomic orientation has been obtained with the Na atom, in an atomic beam and in the vapor in equilibrium with the metal. The orientation effects have been studied by detection of radio-frequency resonance signals in the ground state. Orientation can be increased many times by adding a variable pressure of a foreign gas to the pure Na vapor. Because of the coupling between nuclear spin and electron spin, nuclear orientation is produced at the same time as atomic orientation.

Journal of the Optical Society of AmericaJun 1, 1957223 citations

Observation of polarized alkali atoms in experiments on optical orientation in a He–Rb and He-Cs mixture under conditions of a pulsed gas discharge

Sergei P. Dmitriev, N. A. Dovator, Victor A. Kartoshkin +1 more

It has been demonstrated that optical pumping of alkali atoms (rubidium and cesium) results to a highly efficient indirect optical orientation of metastable He (2 3 S 1 ) atoms. However, in an attempt to perform the inverse experiment (i.e. to receive spin-polarization of alkali atoms upon optical pumping of metastable helium atoms) the result was quite unexpected: the magnetic resonance signal of Cs or Rb atoms was very weak (several hundred times weaker compared to conventional optical pumping of helium in the presence of cesium (rubidium)). We propose an explanation for the unusually small ratio of the magnetic resonance signals from Cs (Rb) and metastable He atoms under condition of optical orientation of He atoms. Except of Cs atoms we are the first to have observed magnetic resonance signals from atoms of 85 Rb and 87 Rb isotopes when using the indirect optical orientation in conditions of helium-rubidium gas discharge plasma. It is shown that the anomaly in the amplitude ratios of the observed MR signals can be explained by the unidirectional action of three different factors (the presence of a large nuclear spin of alkali atoms, depolarization of alkali atoms between collisions, and spin exchange between atoms of rubidium isotopes (for the He-Rb system).It has been demonstrated that optical pumping of alkali atoms (rubidium and cesium) results to a highly efficient indirect optical orientation of metastable He (2 3 S 1 ) atoms. However, in an attempt to perform the inverse experiment (i.e. to receive spin-polarization of alkali atoms upon optical pumping of metastable helium atoms) the result was quite unexpected: the magnetic resonance signal of Cs or Rb atoms was very weak (several hundred times weaker compared to conventional optical pumping of helium in the presence of cesium (rubidium)). We propose an explanation for the unusually small ratio of the magnetic resonance signals from Cs (Rb) and metastable He atoms under condition of optical orientation of He atoms. Except of Cs atoms we are the first to have observed magnetic resonance signals from atoms of 85 Rb and 87 Rb isotopes when using the indirect optical orientation in conditions of helium-rubidium gas discharge plasma. It is shown that the anomaly in the amplitude ratios of the observed MR signals can be explained by the unidirectional action of three different factors (the presence of a large nuclear spin of alkali atoms, depolarization of alkali atoms between collisions, and spin exchange between atoms of rubidium isotopes (for the He-Rb system).

Journal of Physics Conference SeriesDec 1, 20181 citation

Laser–radio-frequency double-resonance spectroscopy of 84−87Rb isotopes trapped in superfluid helium

X. F. Yang, T. Furukawa, T. Wakui +25 more

In this paper, we report on a laser spectroscopy measurement of ${}^{84\ensuremath{-}87}\mathrm{Rb}$ isotopes in superfluid helium (He ii) at 1.8 K using laser--radio-frequency double-resonance spectroscopy. Rb ion beams $(>60$ MeV/u) provided by the RIKEN projectile fragment separator (RIPS) were injected and trapped into He ii. The stopping position of atoms in He ii was precisely confirmed by laser spectroscopy. By optically pumping the trapped Rb isotopes, large atomic spin polarization (up to 40%) of each observed isotope in the ground state was achieved. The laser--radio-frequency double-resonance spectra were observed for stable ${}^{85,87}\mathrm{Rb}$ isotopes as well as for unstable isotopes ${}^{84,84m,86}\mathrm{Rb}$ by scanning a weak magnetic field with a fixed-frequency RF field. From the measured Zeeman splitting, nuclear spin values for ${}^{84m,84\ensuremath{-}87}\mathrm{Rb}$ isotopes were determined with reasonable accuracy. The number of ions injected into He ii for the resonance spectra measurement was on the order of $10{}^{4}$ particles per second. This work may open new opportunities for the study of various particles trapped in condensed helium in several fields.In this paper, we report on a laser spectroscopy measurement of ${}^{84\ensuremath{-}87}\mathrm{Rb}$ isotopes in superfluid helium (He ii) at 1.8 K using laser--radio-frequency double-resonance spectroscopy. Rb ion beams $(>60$ MeV/u) provided by the RIKEN projectile fragment separator (RIPS) were injected and trapped into He ii. The stopping position of atoms in He ii was precisely confirmed by laser spectroscopy. By optically pumping the trapped Rb isotopes, large atomic spin polarization (up to 40%) of each observed isotope in the ground state was achieved. The laser--radio-frequency double-resonance spectra were observed for stable ${}^{85,87}\mathrm{Rb}$ isotopes as well as for unstable isotopes ${}^{84,84m,86}\mathrm{Rb}$ by scanning a weak magnetic field with a fixed-frequency RF field. From the measured Zeeman splitting, nuclear spin values for ${}^{84m,84\ensuremath{-}87}\mathrm{Rb}$ isotopes were determined with reasonable accuracy. The number of ions injected into He ii for the resonance spectra measurement was on the order of $10{}^{4}$ particles per second. This work may open new opportunities for the study of various particles trapped in condensed helium in several fields.

Physical Review ANov 19, 20149 citations

Spin polarization of 85Rb atoms in collisions with optically oriented metastable 4He atoms in alkali–helium plasma

Sergei P. Dmitriev, N. A. Dovator, Victor A. Kartoshkin

We have experimentally detected a signal of magnetic resonance (MR) from 85Rb atoms in the 52 S 1/2 state by measuring the absorption of light from a helium lamp producing optical orientation of metastable 23 S 1 4He atoms in a cell containing alkali metal vapor and gaseous helium at a pressure of 1 Torr. The ratio of MR signal amplitudes in Rb and He atoms did not exceed 10–2. Peculiarities of the formation and observation of the collisional polarization of Rb atoms in alkali–helium plasma are discussed.We have experimentally detected a signal of magnetic resonance (MR) from 85Rb atoms in the 52 S 1/2 state by measuring the absorption of light from a helium lamp producing optical orientation of metastable 23 S 1 4He atoms in a cell containing alkali metal vapor and gaseous helium at a pressure of 1 Torr. The ratio of MR signal amplitudes in Rb and He atoms did not exceed 10–2. Peculiarities of the formation and observation of the collisional polarization of Rb atoms in alkali–helium plasma are discussed.

Technical Physics LettersJan 1, 20166 citations

Optical properties of alkali-metal atoms in pressurized liquid helium

Toshiya Kinoshita, K. Fukuda, Yoshiro Takahashi +1 more

The excitation and emission spectra of alkali-metal atoms (Cs and Rb) in liquid helium are studied. The helium pressure is changed from the saturated vapor pressure to about 25 atm at 1.6 K, under which conditions the liquid helium is in a superfluid state. The pressure shift and broadening of the observed spectra corresponding to the D lines are explained qualitatively by a theoretical calculation based on the spherical atomic bubble model. The Cs ${\mathit{D}}_{2}$ excitation spectra are found to have double peaks, indicating the existence of anisotropic oscillations of the bubble surface. The disappearance of the ${\mathit{D}}_{2}$ emission lines and the pressure-dependent quenching of the Rb ${\mathit{D}}_{1}$ emission lines are also discussed.The excitation and emission spectra of alkali-metal atoms (Cs and Rb) in liquid helium are studied. The helium pressure is changed from the saturated vapor pressure to about 25 atm at 1.6 K, under which conditions the liquid helium is in a superfluid state. The pressure shift and broadening of the observed spectra corresponding to the D lines are explained qualitatively by a theoretical calculation based on the spherical atomic bubble model. The Cs ${\mathit{D}}_{2}$ excitation spectra are found to have double peaks, indicating the existence of anisotropic oscillations of the bubble surface. The disappearance of the ${\mathit{D}}_{2}$ emission lines and the pressure-dependent quenching of the Rb ${\mathit{D}}_{1}$ emission lines are also discussed.

Physical Review AOct 1, 199571 citations

Optical Detection of Nonradiating Alkali Atoms in Solid Helium

T. Eichler, R. Müller-Siebert, Daniel Nettels +2 more

We have detected by optical means nonfluorescing ${}^{85}\mathrm{Rb}$ and ${}^{87}\mathrm{Rb}$ atoms implanted in a body centered cubic ${}^{4}\mathrm{He}$ crystal. In contrast to cesium the resonance fluorescence of rubidium is strongly quenched by the helium matrix, and the weak resonance absorption of the two Rb isotopes was detected using a double resonance technique. From a comparative study of the (optically detected) magnetic resonance spectra of ${}^{85}\mathrm{Rb}$ , ${}^{87}\mathrm{Rb}$ , and ${}^{133}\mathrm{Cs}$ we infer their effective ${g}_{F}$ factors and conclude that they are not perturbed by the He matrix at a level of $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$. We show further that optical pumping of Rb proceeds via depopulation, whereas for Cs it proceeds via repopulation.We have detected by optical means nonfluorescing ${}^{85}\mathrm{Rb}$ and ${}^{87}\mathrm{Rb}$ atoms implanted in a body centered cubic ${}^{4}\mathrm{He}$ crystal. In contrast to cesium the resonance fluorescence of rubidium is strongly quenched by the helium matrix, and the weak resonance absorption of the two Rb isotopes was detected using a double resonance technique. From a comparative study of the (optically detected) magnetic resonance spectra of ${}^{85}\mathrm{Rb}$, ${}^{87}\mathrm{Rb}$, and ${}^{133}\mathrm{Cs}$ we infer their effective ${g}_{F}$ factors and conclude that they are not perturbed by the He matrix at a level of $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$. We show further that optical pumping of Rb proceeds via depopulation, whereas for Cs it proceeds via repopulation.

Physical Review LettersMar 7, 200219 citations

{\mathit{D}}_{1}

(>60

MeV/u) provided by the RIKEN projectile fragment separator (RIPS) were injected and trapped into He ii. The stopping position of atoms in He ii was precisely confirmed by laser spectroscopy. By optically pumping the trapped Rb isotopes, large atomic spin polarization (up to 40%) of each observed isotope in the ground state was achieved. The laser--radio-frequency double-resonance spectra were observed for stable

{}^{85,87}\mathrm{Rb}

isotopes as well as for unstable isotopes

{}^{84,84m,86}\mathrm{Rb}

by scanning a weak magnetic field with a fixed-frequency RF field. From the measured Zeeman splitting, nuclear spin values for ${}^{84m,84\ensuremath{-}87}\mathrm{Rb}$ isotopes were determined with reasonable accuracy. The number of ions injected into He ii for the resonance spectra measurement was on the order of

10{}^{4}

particles per second. This work may open new opportunities for the study of various particles trapped in condensed helium in several fields.

{\mathit{D}}_{2}

excitation spectra are found to have double peaks, indicating the existence of anisotropic oscillations of the bubble surface. The disappearance of the

{\mathit{D}}_{2}

emission lines and the pressure-dependent quenching of the Rb

{\mathit{D}}_{1}

emission lines are also discussed.

We have detected by optical means nonfluorescing

{}^{85}\mathrm{Rb}

and

{}^{87}\mathrm{Rb}

atoms implanted in a body centered cubic

{}^{4}\mathrm{He}

crystal. In contrast to cesium the resonance fluorescence of rubidium is strongly quenched by the helium matrix, and the weak resonance absorption of the two Rb isotopes was detected using a double resonance technique. From a comparative study of the (optically detected) magnetic resonance spectra of

{}^{85}\mathrm{Rb}

{}^{87}\mathrm{Rb}

, and

{}^{133}\mathrm{Cs}

we infer their effective

{g}_{F}

factors and conclude that they are not perturbed by the He matrix at a level of $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$. We show further that optical pumping of Rb proceeds via depopulation, whereas for Cs it proceeds via repopulation.