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

Physical Review Letters

Proposed E1−M1 Interference Experiment in Hydrogenic Ions to Measure Spin Polarization

G. W. F. Drake

Published Jun 26, 1978• 7 citations
Publisher

Abstract

It is shown that in the Stark quenching of a spin-polarized beam of metastable hydrogenic ions, a measurable right-left asymmetry can be produced in the emitted radiation which is proportional to the degree of spin polarization. The effect, which has previously been observed in absorption in neutral cesium and thallium, is due to interference between spontaneous magnetic dipole and induced electric dipole decay modes. Asymmetry measurements offer a simple means of determining the degree of spin polarization in the heavier hydrogenic ions.

DOI
10.1103/physrevlett.40.1705

Related papers

E1−E1 damping interference in the electric field quenching of spin-polarized He+2s12 ions

Adriaan J. van Wijngaarden, Reinhard K. B. Helbing, J. Patel +1 more

When a beam of spin-polarized metastable ${\mathrm{He}}^{+}2{s}_{\frac{1}{2}}$ ions is quenched by an electric field $\stackrel{\ensuremath{\rightarrow}}{\mathrm{E}}$, the emitted radiation intensity contains an asymmetry term proportional to $(\stackrel{^}{k}\ifmmode\cdot\else\textperiodcentered\fi{}\stackrel{^}{E})(\stackrel{\ensuremath{\rightarrow}}{\mathrm{P}}\ifmmode\cdot\else\textperiodcentered\fi{}\stackrel{^}{k}\ifmmode\times\else\texttimes\fi{}\stackrel{^}{E})$ where $\stackrel{\ensuremath{\rightarrow}}{\mathrm{P}}$ is the spin-polarization vector and $\stackrel{^}{k}$ is the direction of observation. The resulting asymmetry is nearly proportional to the level width of the $2{p}_{\frac{1}{2}}$ state in ${\mathrm{He}}^{+}$. The experiment provides the first observation of the asymmetry. The measured asymmetry is (0.007 69\ifmmode\pm\else\textpm\fi{}0.000 10) in agreement with the theoretical value 0.007 618 and corresponds to a lifetime ${\ensuremath{\tau}}_{2p}=(0.988\ifmmode\pm\else\textpm\fi{}0.013)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$ sec.

Physical Review A•Feb 1, 1982•9 citations

Measurement of a linear Stark interference effect on the rubidiumD1 absorption line

Xu Chen, Frank R. Huang‐Hellinger, B. R. Heckel +1 more

We have measured the magnetic dipole (M1) and electric quadrupole (E2) amplitudes in the D1 transition of rubidium atoms placed in a static electric field, ${\mathit{scrE}\ensuremath{\rightarrow}}_{\mathit{s}}$. The interference of the Stark induced M1 and E2 amplitudes with the normal E1 amplitude gives the atomic absorptivity a linear dependence on ${\mathit{scrE}\ensuremath{\rightarrow}}_{\mathit{s}}$ and on the atomic spin polarization. We find that the fractional change in absorptivity due to the Stark interference is ${\mathit{a}}_{\mathit{M}1}$+${\mathit{a}}_{\mathit{E}2}$=(-2.37\ifmmode\pm\else\textpm\fi{}0.37\ifmmode\pm\else\textpm\fi{}0.28)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}8}$ (kV/cm${)}^{\mathrm{\ensuremath{-}}1}$.

Physical Review A•Dec 1, 1994•4 citations

Asymmetry in emission of photons with left- and right-hand circular polarizations in two-photon decay

K. N. Lyashchenko, Victoria A. Knyazeva, O. Yu. Andreev +1 more

Two-photon decay of the $2s$ state in H-like ions is investigated. We report that asymmetry in the emission of photons with left- and right-hand circular polarizations can be observed in this transition if the initial state has a certain polarization. This asymmetry can be used to measure the polarization of ion beams.

Physical Review A•Jul 1, 2021•0 citations

Complete linear polarization of Lyman-αradiation from metastable hydrogen atoms in external electric fields

Wolfgang Harbich, R. Hippler, Hans Kleinpoppen +1 more

The linear Stark effect of hydrogen was investigated for the metastable H(2s) state measuring the degree of linear polarization of field-induced Lyman-\ensuremath{\alpha} radiation. For sufficiently large electric fields (few kV/cm) the measured degree of linear polarization P is almost complete (P\ensuremath{\approxeq}-100%). This result is in excellent agreement with theoretical predictions, if the fine structure of hydrogen is taken into account.

Physical Review A•Apr 1, 1989•13 citations

Test of the anisotropy method for Lamb-shift measurements—theory and experiment

G. W. F. Drake, Péter Faragó, Adriaan J. van Wijngaarden

We show that a measurement of the anisotropy in the angular distribution of the quenching radiation emitted by metastable hydrogen and deuterium atoms in an electric field can be used to determine the Lamb shift to an accuracy of at least \ifmmode\pm\else\textpm\fi{}0.1%. The method can be extended to the hydrogenic ions, where it offers several advantages over the quench-rate technique used in earlier measurements. The experiment is interpreted by means of a nonperturbative theory of the quenching process, which includes hyperfine structure and time-dependent effects. In the limit of zero field strength, the anisotropies of H and D are measured to be 0.139 01 \ifmmode\pm\else\textpm\fi{} 0.000 12 and 0.141 21 \ifmmode\pm\else\textpm\fi{} 0.000 14, while the theoretical values are 0.139 078 and 0.141 30, respectively. The corresponding Lamb shifts are 1057.3 \ifmmode\pm\else\textpm\fi{} 0.9 MHz and 1058.7 \ifmmode\pm\else\textpm\fi{} 1.1 MHz.

Physical Review A•May 1, 1975•30 citations

Polarization of Lyman- α Radiation Emitted in Electron Collisions with Hydrogen Atoms and Molecules

William R. Ott, Walter E. Kauppila, Wade L. Fite

The polarizations of Lyman-$\ensuremath{\alpha}$ radiation produced (i) by electron impact on atomic and molecular hydrogen and (ii) by electric field quenching of metastable $2S$ hydrogen atoms have been measured. The polarization analyzer was a LiF crystal set at the Brewster angle, with reflected radiation being detected by an iodine-vapor photon counter. Generally good agreement between the measured polarization fractions and recent theoretical predictions was found. The radiation produced by quenching metastable atoms in an electric field was found to be polarized with a polarization fraction of -0.30\ifmmode\pm\else\textpm\fi{}0.02, which compares with the theoretical value -0.323.

Physical Review A•Apr 1, 1970•118 citations
It is shown that in the Stark quenching of a spin-polarized beam of metastable hydrogenic ions, a measurable right-left asymmetry can be produced in the emitted radiation which is proportional to the degree of spin polarization. The effect, which has previously been observed in absorption in neutral cesium and thallium, is due to interference between spontaneous magnetic dipole and induced electric dipole decay modes. Asymmetry measurements offer a simple means of determining the degree of spin polarization in the heavier hydrogenic ions.
When a beam of spin-polarized metastable He+2s12{\mathrm{He}}^{+}2{s}_{\frac{1}{2}}He+2s21​​ ions is quenched by an electric field $\stackrel{\ensuremath{\rightarrow}}{\mathrm{E}}$, the emitted radiation intensity contains an asymmetry term proportional to $(\stackrel{^}{k}\ifmmode\cdot\else\textperiodcentered\fi{}\stackrel{^}{E})(\stackrel{\ensuremath{\rightarrow}}{\mathrm{P}}\ifmmode\cdot\else\textperiodcentered\fi{}\stackrel{^}{k}\ifmmode\times\else\texttimes\fi{}\stackrel{^}{E})$ where $\stackrel{\ensuremath{\rightarrow}}{\mathrm{P}}$ is the spin-polarization vector and $\stackrel{^}{k}$ is the direction of observation. The resulting asymmetry is nearly proportional to the level width of the 2p122{p}_{\frac{1}{2}}2p21​​ state in He+{\mathrm{He}}^{+}He+. The experiment provides the first observation of the asymmetry. The measured asymmetry is (0.007 69\ifmmode\pm\else\textpm\fi{}0.000 10) in agreement with the theoretical value 0.007 618 and corresponds to a lifetime ${\ensuremath{\tau}}_{2p}=(0.988\ifmmode\pm\else\textpm\fi{}0.013)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$ sec.
We have measured the magnetic dipole (M1) and electric quadrupole (E2) amplitudes in the D1 transition of rubidium atoms placed in a static electric field, ${\mathit{scrE}\ensuremath{\rightarrow}}_{\mathit{s}}$. The interference of the Stark induced M1 and E2 amplitudes with the normal E1 amplitude gives the atomic absorptivity a linear dependence on ${\mathit{scrE}\ensuremath{\rightarrow}}_{\mathit{s}}$ and on the atomic spin polarization. We find that the fractional change in absorptivity due to the Stark interference is aM1{\mathit{a}}_{\mathit{M}1}aM1​+aE2{\mathit{a}}_{\mathit{E}2}aE2​=(-2.37\ifmmode\pm\else\textpm\fi{}0.37\ifmmode\pm\else\textpm\fi{}0.28)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}8}$ (kV/cm${)}^{\mathrm{\ensuremath{-}}1}$.
Two-photon decay of the 2s2s2s state in H-like ions is investigated. We report that asymmetry in the emission of photons with left- and right-hand circular polarizations can be observed in this transition if the initial state has a certain polarization. This asymmetry can be used to measure the polarization of ion beams.
We show that a measurement of the anisotropy in the angular distribution of the quenching radiation emitted by metastable hydrogen and deuterium atoms in an electric field can be used to determine the Lamb shift to an accuracy of at least \ifmmode\pm\else\textpm\fi{}0.1%. The method can be extended to the hydrogenic ions, where it offers several advantages over the quench-rate technique used in earlier measurements. The experiment is interpreted by means of a nonperturbative theory of the quenching process, which includes hyperfine structure and time-dependent effects. In the limit of zero field strength, the anisotropies of H and D are measured to be 0.139 01 \ifmmode\pm\else\textpm\fi{} 0.000 12 and 0.141 21 \ifmmode\pm\else\textpm\fi{} 0.000 14, while the theoretical values are 0.139 078 and 0.141 30, respectively. The corresponding Lamb shifts are 1057.3 \ifmmode\pm\else\textpm\fi{} 0.9 MHz and 1058.7 \ifmmode\pm\else\textpm\fi{} 1.1 MHz.
The polarizations of Lyman-$\ensuremath{\alpha}$ radiation produced (i) by electron impact on atomic and molecular hydrogen and (ii) by electric field quenching of metastable 2S2S2S hydrogen atoms have been measured. The polarization analyzer was a LiF crystal set at the Brewster angle, with reflected radiation being detected by an iodine-vapor photon counter. Generally good agreement between the measured polarization fractions and recent theoretical predictions was found. The radiation produced by quenching metastable atoms in an electric field was found to be polarized with a polarization fraction of -0.30\ifmmode\pm\else\textpm\fi{}0.02, which compares with the theoretical value -0.323.