Physical Review Letters

Resonance in Singlet-Triplet Mixing in Two-Electron Systems Caused by Perturbing Configurations

Herbert H. Rinneberg, Jörg Neukammer

Published Jul 12, 1982• 34 citations

Abstract

The hyperfine structure of the $6snd^{1}D_{2}$ ($10<~n<~50$) Rydberg states of barium has been measured and analyzed in terms of singlet-triplet mixing. A dispersionlike resonant behavior of the mixing coefficient $\ensuremath{\Omega}$ was observed for barium and strontium in the vicinity of doubly excited configurations. In barium strong disagreement with multichannel-quantum-defect-theory wave functions was found. The present results are compared with the spin polarization and anisotropy of photoelectrons.

DOI: 10.1103/physrevlett.49.124

Related papers

Configuration interaction and singlet-triplet mixing probed by hyperfine structure of 6s14d1D2and3D1,2,3barium Rydberg states

Jörg Neukammer, Herbert H. Rinneberg

The hyperfine structure of the 6s14d configuration of barium has been measured by optical-optical double resonance. From the observed positions for the hyperfine components of the 1 D 2 and 3 D 1,2,3 Rydberg states, the singlet and triplet character as well as the amount of admixture of the 5d7d perturbing configuration was deduced. Although agreeing qualitatively, the authors' results differ quantitatively from predictions made by multichannel quantum defect theory (MQDT).

Journal of Physics B Atomic and Molecular PhysicsNov 14, 198213 citations

Hyperfine structure and three-channel quantum-defect theory of 6sndD21 Rydberg states of Ba

Herbert H. Rinneberg, Jörg Neukammer

Physical Review AApr 1, 198337 citations

HIGH RESOLUTION LASER SPECTROSCOPY OF ODD-PARITY BARIUM RYDBERG STATES POPULATED BY FORBIDDEN ATOMIC TRANSITIONS

Herbert H. Rinneberg, Jörg Neukammer

Le Journal de Physique ColloquesNov 1, 19836 citations

Influence of Singlet-Triplet Mixing on the Hyperfine Structure of 5snd Rydberg States in Sr87

R. Beigang, Eckart Matthias, Andre Timmermann

Physical Review LettersAug 3, 198152 citations

Singlet-triplet mixing in 4snd Rydberg states of Ca

R. Beigang, K. Lücke, Andre Timmermann

Physical Review AJan 1, 198321 citations

Multichannel quantum defect theory of strontium bound Rydberg states

Christophe L. Vaillant, M P A Jones, R. M. Potvliege

arXiv:1402.5802Journal of Physics B Atomic Molecular and Optical PhysicsJul 15, 201440 citations

Physical Review Letters

Resonance in Singlet-Triplet Mixing in Two-Electron Systems Caused by Perturbing Configurations

Herbert H. Rinneberg, Jörg Neukammer

Published Jul 12, 1982• 34 citations

Publisher

Abstract

The hyperfine structure of the

6snd^{1}D_{2}

(

10<~n<~50

) Rydberg states of barium has been measured and analyzed in terms of singlet-triplet mixing. A dispersionlike resonant behavior of the mixing coefficient

\ensuremath{\Omega}

was observed for barium and strontium in the vicinity of doubly excited configurations. In barium strong disagreement with multichannel-quantum-defect-theory wave functions was found. The present results are compared with the spin polarization and anisotropy of photoelectrons.

DOI: 10.1103/physrevlett.49.124

Related papers

Configuration interaction and singlet-triplet mixing probed by hyperfine structure of 6s14d1D2and3D1,2,3barium Rydberg states

Jörg Neukammer, Herbert H. Rinneberg

Journal of Physics B Atomic and Molecular PhysicsNov 14, 198213 citations

Hyperfine structure and three-channel quantum-defect theory of 6sndD21 Rydberg states of Ba

Herbert H. Rinneberg, Jörg Neukammer

The hyperfine structure of $6snd^{1}D_{2}$ Rydberg states of $^{135,137}\mathrm{Ba}$ is reported for principal quantum numbers ranging between $n=10$ and $n=50$ . From our data, singlet-triplet mixing coefficients have been deduced. A three-channel quantum-defect model has been used to analyze the resonance in singlet-triplet mixing of $6snd^{1}D_{2} \mathrm{and} ^{3}D_{2}$ Rydberg states in the vicinity of the $5d7d^{1}D_{2}$ perturber. For the determination of the scattering matrix, hyperfine-structure data were found to be essential. Good agreement has been achieved between calculated and experimental singlet-triplet mixing coefficients.The hyperfine structure of $6snd^{1}D_{2}$ Rydberg states of $^{135,137}\mathrm{Ba}$ is reported for principal quantum numbers ranging between $n=10$ and $n=50$. From our data, singlet-triplet mixing coefficients have been deduced. A three-channel quantum-defect model has been used to analyze the resonance in singlet-triplet mixing of $6snd^{1}D_{2} \mathrm{and} ^{3}D_{2}$ Rydberg states in the vicinity of the $5d7d^{1}D_{2}$ perturber. For the determination of the scattering matrix, hyperfine-structure data were found to be essential. Good agreement has been achieved between calculated and experimental singlet-triplet mixing coefficients.

Physical Review AApr 1, 198337 citations

HIGH RESOLUTION LASER SPECTROSCOPY OF ODD-PARITY BARIUM RYDBERG STATES POPULATED BY FORBIDDEN ATOMIC TRANSITIONS

Herbert H. Rinneberg, Jörg Neukammer

Odd-parity barium Rydberg states have been populated by stepwise excitation via M1-E1 and E2-E1 transitions, starting from the 6s2 1S0 ground state. Using two cw dye ring lasers and employing thermionic detection, Doppler-free spectra of 6snp 1,3P and 6snf 1,3F Rydberg states have been recorded with excellent signal/noise ratios. A systematic study of the hyperfine structure of 6snp 1P1 Rydberg states has been carried out. Between n=20 and n=23 a resonance in singlet-triplet mixing occurs caused by configuration interaction with the 5d8p 1P1 perturbing state, located close to the first ionization limit. Our results are in disagreement with an existing multichannel quantum defect analysis of this series. The singlet-triplet mixing of 6snp 1P1 and 6snd 1D2 Rydberg series is compared.Odd-parity barium Rydberg states have been populated by stepwise excitation via M1-E1 and E2-E1 transitions, starting from the 6s2 1S0 ground state. Using two cw dye ring lasers and employing thermionic detection, Doppler-free spectra of 6snp 1,3P and 6snf 1,3F Rydberg states have been recorded with excellent signal/noise ratios. A systematic study of the hyperfine structure of 6snp 1P1 Rydberg states has been carried out. Between n=20 and n=23 a resonance in singlet-triplet mixing occurs caused by configuration interaction with the 5d8p 1P1 perturbing state, located close to the first ionization limit. Our results are in disagreement with an existing multichannel quantum defect analysis of this series. The singlet-triplet mixing of 6snp 1P1 and 6snd 1D2 Rydberg series is compared.

Le Journal de Physique ColloquesNov 1, 19836 citations

Influence of Singlet-Triplet Mixing on the Hyperfine Structure of 5snd Rydberg States in Sr87

R. Beigang, Eckart Matthias, Andre Timmermann

A systematic study of the hyperfine structure of $5snd$ $^{1}D_{2}$ and $^{3}D_{2}$ states of $^{87}\mathrm{Sr}$ was carried out by Doppler-free two-photon excitation. In the region of strong singlet-triplet mixing around $n=16$ , the hyperfine structure exhibits a marked $n$ dependence which is related to the amount of singlet-triplet mixing.A systematic study of the hyperfine structure of $5snd$ $^{1}D_{2}$ and $^{3}D_{2}$ states of $^{87}\mathrm{Sr}$ was carried out by Doppler-free two-photon excitation. In the region of strong singlet-triplet mixing around $n=16$, the hyperfine structure exhibits a marked $n$ dependence which is related to the amount of singlet-triplet mixing.

Physical Review LettersAug 3, 198152 citations

Singlet-triplet mixing in 4snd Rydberg states of Ca

R. Beigang, K. Lücke, Andre Timmermann

Singlet-triplet mixing of $4snd ^{1}D_{2}$ and $^{3}D_{2}$ states of Ca was determined between principal quantum numbers $7<~n<~42$ with the use of Doppler-free two-photon spectroscopy. The hyperfine structure of the $4snd ^{1}D_{2}$ states was used to probe admixtures of triplet character into the singlet wave functions. It turned out that, in the region of series crossings, an enlarged singlet-triplet mixing was observed.Singlet-triplet mixing of $4snd ^{1}D_{2}$ and $^{3}D_{2}$ states of Ca was determined between principal quantum numbers $7<~n<~42$ with the use of Doppler-free two-photon spectroscopy. The hyperfine structure of the $4snd ^{1}D_{2}$ states was used to probe admixtures of triplet character into the singlet wave functions. It turned out that, in the region of series crossings, an enlarged singlet-triplet mixing was observed.

Physical Review AJan 1, 198321 citations

Multichannel quantum defect theory of strontium bound Rydberg states

Christophe L. Vaillant, M P A Jones, R. M. Potvliege

Abstract Using the reactance matrix approach, we systematically develop new multichannel quantum defect theory (MQDT) models for the singlet and triplet S, P, D and F states of strontium below the first ionization limit, based on improved energy level measurements. The new models reveal additional insights into the character of doubly excited perturber states, and the improved energy level measurements for certain series allow fine structure to be resolved for those series’ perturbers. Comparison between the predictions of the new models and those of previous empirical and ab initio studies reveals good agreement with most series; however, some discrepancies are highlighted. Using the MQDT wave functions derived from our models we calculate other observables such as Landé -factors and radiative lifetimes. The analysis reveals the impact of perturbers on the Rydberg state properties of divalent atoms, highlighting the importance of including two-electron effects in the calculations of these properties. The work enables future investigations of properties such as Stark maps and long-range interactions of Rydberg states of strontium.Abstract Using the reactance matrix approach, we systematically develop new multichannel quantum defect theory (MQDT) models for the singlet and triplet S, P, D and F states of strontium below the first ionization limit, based on improved energy level measurements. The new models reveal additional insights into the character of doubly excited perturber states, and the improved energy level measurements for certain series allow fine structure to be resolved for those series’ perturbers. Comparison between the predictions of the new models and those of previous empirical and ab initio studies reveals good agreement with most series; however, some discrepancies are highlighted. Using the MQDT wave functions derived from our models we calculate other observables such as Landé -factors and radiative lifetimes. The analysis reveals the impact of perturbers on the Rydberg state properties of divalent atoms, highlighting the importance of including two-electron effects in the calculations of these properties. The work enables future investigations of properties such as Stark maps and long-range interactions of Rydberg states of strontium.

arXiv:1402.5802Journal of Physics B Atomic Molecular and Optical PhysicsJul 15, 201440 citations

The hyperfine structure of the

6snd^{1}D_{2}

(

10<~n<~50

) Rydberg states of barium has been measured and analyzed in terms of singlet-triplet mixing. A dispersionlike resonant behavior of the mixing coefficient

\ensuremath{\Omega}

The hyperfine structure of

6snd^{1}D_{2}

Rydberg states of

^{135,137}\mathrm{Ba}

is reported for principal quantum numbers ranging between

n=10

and

n=50

. From our data, singlet-triplet mixing coefficients have been deduced. A three-channel quantum-defect model has been used to analyze the resonance in singlet-triplet mixing of

6snd^{1}D_{2} \mathrm{and} ^{3}D_{2}

Rydberg states in the vicinity of the

5d7d^{1}D_{2}

perturber. For the determination of the scattering matrix, hyperfine-structure data were found to be essential. Good agreement has been achieved between calculated and experimental singlet-triplet mixing coefficients.

A systematic study of the hyperfine structure of

5snd

^{1}D_{2}

and

^{3}D_{2}

states of

^{87}\mathrm{Sr}

was carried out by Doppler-free two-photon excitation. In the region of strong singlet-triplet mixing around

n=16

, the hyperfine structure exhibits a marked

n

dependence which is related to the amount of singlet-triplet mixing.

Singlet-triplet mixing of

4snd ^{1}D_{2}

and

^{3}D_{2}

states of Ca was determined between principal quantum numbers

7<~n<~42

with the use of Doppler-free two-photon spectroscopy. The hyperfine structure of the

4snd ^{1}D_{2}

states was used to probe admixtures of triplet character into the singlet wave functions. It turned out that, in the region of series crossings, an enlarged singlet-triplet mixing was observed.