The longitudinal electronic spin relaxation time of Cs atoms optically polarized in superfluid helium (He II, 1.5 K) has been measured with special care to cope with a serious decrease in the number of Cs atoms in the observation region. This decrease, mainly caused by helium convection in introducing the atoms into He II by laser sputtering, was significantly reduced using a new atom implantation method. Combined with a careful correction for the number of atoms, we have determined the relaxation time to be 2.24(19) s or longer, roughly twice as long as that in solid He.The longitudinal electronic spin relaxation time of Cs atoms optically polarized in superfluid helium (He II, 1.5 K) has been measured with special care to cope with a serious decrease in the number of Cs atoms in the observation region. This decrease, mainly caused by helium convection in introducing the atoms into He II by laser sputtering, was significantly reduced using a new atom implantation method. Combined with a careful correction for the number of atoms, we have determined the relaxation time to be 2.24(19) s or longer, roughly twice as long as that in solid He.

Physical Review LettersMar 8, 200624 citations

Spectroscopy and dynamics of neutral atoms in superfluid helium

Q. Hui, John L. Persson, Jaap H. M. Beijersbergen +1 more

The European Physical Journal BSep 1, 199538 citations

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

Toshiya Kinoshita, Yoshiro Takahashi, T. Yabuzaki

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.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.

Physical review. B, Condensed matterFeb 1, 199457 citations

Microscopic Theory of Superfluid Helium

Pierre C. Hohenberg, Paul C. Martin

Annals of PhysicsApr 1, 200011 citations

What do we know about atomic bubbles in helium crystals?

T. Eichler, Klaus Winkler, S. Lang +2 more

We present new results on the properties of Celsium and Rubidium atoms trapped in crystalline helium matrices. We have extended the measurements of optical excitation spectra and excited state lifetimes, previously performed in superfluid helium, to solid helium. Cs atoms in the hcp phase of 4He exhibit several distinctive features, such as dipole-forbidden transitions and zero-field magnetic resonance lines. We interpret these features as being due to static quadrupolar deformations of the local trapping sites (atomic bubbles). The degree of deformation of the bubbles can be obtained by comparing hyperfine coupling constants in the cubic and hexagonal phases. We have investigated in detail optical pumping of Cs in solid helium, and have gained new insights into the pumping mechanism. We have also succeeded, for the first time, in detecting Rb and Rb in solid helium, by applying an absorption technique, based on driven spin precession.We present new results on the properties of Celsium and Rubidium atoms trapped in crystalline helium matrices. We have extended the measurements of optical excitation spectra and excited state lifetimes, previously performed in superfluid helium, to solid helium. Cs atoms in the hcp phase of 4He exhibit several distinctive features, such as dipole-forbidden transitions and zero-field magnetic resonance lines. We interpret these features as being due to static quadrupolar deformations of the local trapping sites (atomic bubbles). The degree of deformation of the bubbles can be obtained by comparing hyperfine coupling constants in the cubic and hexagonal phases. We have investigated in detail optical pumping of Cs in solid helium, and have gained new insights into the pumping mechanism. We have also succeeded, for the first time, in detecting Rb and Rb in solid helium, by applying an absorption technique, based on driven spin precession.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIEFeb 25, 19990 citations

Stabilization of nitrogen atoms in superfluid helium

Eugene B. Gordon, Леонид Павлович Межов-Деглин, O. F. Pugachev

Jan 20, 197421 citations

{\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.