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

Journal of Physics B Atomic Molecular and Optical Physics

Electric-field effects on the photodetachment of below the threshold

H. Bachau, Fernando Martı́n

Published Apr 28, 1996• 8 citations
Publisher

Abstract

We have implemented an integrable method with B-spline basis which allows us to calculate photodetachment cross sections of the ion in the presence of a constant electric field. The behaviour of the Feshbach resonances lying below the N = 2 and N = 3 thresholds is analysed in detail. Further insight on the relative importance of autoionization and tunnelling is provided by using a stabilization procedure. Our results permit us to explain most of the experimental findings and show the existence of resonance structures previously unobserved.

DOI
10.1088/0953-4075/29/8/010

Related papers

Negative-ion photodetachment in an electric field

Hin-Yiu Wong, A. R. P. Rau, Chris H. Greene

A multichannel study of the photodetachment of a negative ion such as ${\mathrm{S}}^{\mathrm{\ensuremath{-}}}$ in the presence of a constant electric field is presented. The analysis is carried out as a series of frame transformations for the outgoing photoelectron. An earlier analysis in the absence of the external field is now augmented by the further transformations from spherical to cylindrical symmetry that are required. The interplay between the various thresholds due to fine structure in the negative ion and residual atom and the effects of the external field are analytically treated. The net effect is to eliminate the thresholds, to induce modulations in the detachment cross section, and to introduce field-assisted-tunneling contributions to the photodetachment. Numerical illustrations are provided. Our treatment closely parallels similar treatments of photoionization of neutral atoms in an electric field and of photodetachment in a magnetic field.

Physical Review A•Apr 1, 1988•59 citations

Photodetachment of H− in an electric field

M. L. Du, J. B. Delos

A simple analytic formula for the photodetachment cross section of ${\mathrm{H}}^{\mathrm{\ensuremath{-}}}$ in an electric field is derived. The formula becomes identical to a formula derived many years ago in the vanishing-field limit. Three special features appear in the cross section in the presence of an electric field: a quantum tunneling effect, a new threshold law, and oscillations. These appear when the photon energy is, respectively, less than, equal to, or greater than the binding energy of ${\mathrm{H}}^{\mathrm{\ensuremath{-}}}$. Enough information is provided in this paper so that one can calculate the cross section quickly.

Physical Review A•Dec 1, 1988•177 citations

s-wave photodetachment in a static electric field

N. D. Gibson, B. J. Davies, Daniel J. Larson

Photodetachment from negative ions in a static electric field has been studied using ${\mathrm{Cl}}^{\mathrm{\ensuremath{-}}}$ and ${\mathrm{S}}^{\mathrm{\ensuremath{-}}}$. These experiments were done with greater precision than previous studies and allow a quantitative comparison of data with theory. A 10-keV ion beam was sent through a region with fields of up to 1.5 kV/cm applied parallel to the beam velocity. A pulsed dye-laser beam, perpendicular to the ion beam, photoneutralized the ions. The relative cross sections were measured by detecting the resulting fast neutral atoms. Detachment below threshold and oscillations on the cross section above threshold were observed near the ${\mathrm{S}}^{\mathrm{\ensuremath{-}}}$ threshold at 16 269.5 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ and near the ${\mathrm{Cl}}^{\mathrm{\ensuremath{-}}}$ threshold at 29 138.3 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$. The phase of the oscillations in the data is in good agreement with predictions for s-wave photodetachment in a static electric field, but the amplitude of the oscillations is found to be slightly reduced.

Physical Review A•Mar 1, 1993•40 citations

Shifts of photodetachment thresholds and induced shape resonances of H− in an electric field

Bin Zhou, C. D. Lin

The photodetachment of ${\mathrm{H}}^{\mathrm{\ensuremath{-}}}$ near the H(N=4) and H(N=5) thresholds in an external electric field is studied theoretically. The recently observed photodetachment threshold shifts of Halka et al. are interpreted in terms of the shifts of the barrier heights of the hyperspherical potential curves as the electric field strength is varied. It is shown that higher members of the zero-field Feshbach resonances can emerge as field-induced shape resonances in an electric field.

Physical Review Letters•Dec 7, 1992•7 citations

Static electric-field effects in the photodetachment of Cs− at the 3P resonance region

A.A. Khuskivadze, I. I. Fabrikant, Uwe Thumm

We calculated near-threshold photodetachment cross sections for ${\mathrm{Cs}}^{\ensuremath{-}}$ in the presence of a dc electric field using three different approaches: the frame-transformation method with and without rescattering effects and the Kirchhoff-integral approach. Radial wave functions for the electronic motion were obtained using the Pauli equation method with a model potential describing the effective electron-atom interaction. Our results demonstrate the inadequacy of the frame-transformation method in the ${}^{3}P$ resonance region even for weak fields $(E<10\mathrm{k}\mathrm{V}/\mathrm{c}\mathrm{m}).$ We show that the triplet and singlet contributions to the total cross section can be manipulated by varying the external electric field. This can enhance spin-orbit effects in the photodetachment process and create more favorable conditions in the experiment for the observation of the lowest ${}^{3}P$ resonance in ${\mathrm{Cs}}^{\ensuremath{-}}.$

Physical Review A•Dec 10, 2003•4 citations

Threshold behaviour in photodetachment into a final state with large negative polarizability

Johan Rohlén, Anton O. Lindahl, Hannes Hultgren +3 more

In a recent experiment, Lindahl et al. ( Lindahl A. O. et al. , Phys. Rev. Lett. , 108 (2012) 033004) observed a new threshold behavior in the photodetachment of the potassium negative ion when the residual atom is left in the state. Unfortunately the resonance close to threshold made it more difficult to apply the semi-classical model that was developed to describe the threshold behavior. In this paper we present a study of the threshold behavior of the partial cross-section in the photodetachment of the sodium negative ion. The experiment was conducted using a collinear beams apparatus where the detection was performed using a resonance ionization scheme. We observe the same threshold behavior as in the previous experiment, but without any obfuscating resonance. The model derived in the previous paper is found to fit the observed cross-section up to 35 meV above threshold. The present experiment clearly demonstrates the threshold behaviour for the fundamental process of a free electron moving in the field of an atom with a large negative polarizability.

Europhysics Letters (EPL)•May 30, 2014•5 citations
We have implemented an integrable method with B-spline basis which allows us to calculate photodetachment cross sections of the ion in the presence of a constant electric field. The behaviour of the Feshbach resonances lying below the N = 2 and N = 3 thresholds is analysed in detail. Further insight on the relative importance of autoionization and tunnelling is provided by using a stabilization procedure. Our results permit us to explain most of the experimental findings and show the existence of resonance structures previously unobserved.
A multichannel study of the photodetachment of a negative ion such as ${\mathrm{S}}^{\mathrm{\ensuremath{-}}}$ in the presence of a constant electric field is presented. The analysis is carried out as a series of frame transformations for the outgoing photoelectron. An earlier analysis in the absence of the external field is now augmented by the further transformations from spherical to cylindrical symmetry that are required. The interplay between the various thresholds due to fine structure in the negative ion and residual atom and the effects of the external field are analytically treated. The net effect is to eliminate the thresholds, to induce modulations in the detachment cross section, and to introduce field-assisted-tunneling contributions to the photodetachment. Numerical illustrations are provided. Our treatment closely parallels similar treatments of photoionization of neutral atoms in an electric field and of photodetachment in a magnetic field.
A simple analytic formula for the photodetachment cross section of ${\mathrm{H}}^{\mathrm{\ensuremath{-}}}$ in an electric field is derived. The formula becomes identical to a formula derived many years ago in the vanishing-field limit. Three special features appear in the cross section in the presence of an electric field: a quantum tunneling effect, a new threshold law, and oscillations. These appear when the photon energy is, respectively, less than, equal to, or greater than the binding energy of ${\mathrm{H}}^{\mathrm{\ensuremath{-}}}$. Enough information is provided in this paper so that one can calculate the cross section quickly.
Photodetachment from negative ions in a static electric field has been studied using ${\mathrm{Cl}}^{\mathrm{\ensuremath{-}}}$ and ${\mathrm{S}}^{\mathrm{\ensuremath{-}}}$. These experiments were done with greater precision than previous studies and allow a quantitative comparison of data with theory. A 10-keV ion beam was sent through a region with fields of up to 1.5 kV/cm applied parallel to the beam velocity. A pulsed dye-laser beam, perpendicular to the ion beam, photoneutralized the ions. The relative cross sections were measured by detecting the resulting fast neutral atoms. Detachment below threshold and oscillations on the cross section above threshold were observed near the ${\mathrm{S}}^{\mathrm{\ensuremath{-}}}$ threshold at 16 269.5 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ and near the ${\mathrm{Cl}}^{\mathrm{\ensuremath{-}}}$ threshold at 29 138.3 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$. The phase of the oscillations in the data is in good agreement with predictions for s-wave photodetachment in a static electric field, but the amplitude of the oscillations is found to be slightly reduced.
The photodetachment of ${\mathrm{H}}^{\mathrm{\ensuremath{-}}}$ near the H(N=4) and H(N=5) thresholds in an external electric field is studied theoretically. The recently observed photodetachment threshold shifts of Halka et al. are interpreted in terms of the shifts of the barrier heights of the hyperspherical potential curves as the electric field strength is varied. It is shown that higher members of the zero-field Feshbach resonances can emerge as field-induced shape resonances in an electric field.
We calculated near-threshold photodetachment cross sections for ${\mathrm{Cs}}^{\ensuremath{-}}$ in the presence of a dc electric field using three different approaches: the frame-transformation method with and without rescattering effects and the Kirchhoff-integral approach. Radial wave functions for the electronic motion were obtained using the Pauli equation method with a model potential describing the effective electron-atom interaction. Our results demonstrate the inadequacy of the frame-transformation method in the 3P{}^{3}P3P resonance region even for weak fields (E<10kV/cm).(E<10\mathrm{k}\mathrm{V}/\mathrm{c}\mathrm{m}).(E<10kV/cm). We show that the triplet and singlet contributions to the total cross section can be manipulated by varying the external electric field. This can enhance spin-orbit effects in the photodetachment process and create more favorable conditions in the experiment for the observation of the lowest 3P{}^{3}P3P resonance in ${\mathrm{Cs}}^{\ensuremath{-}}.$
In a recent experiment, Lindahl et al. ( Lindahl A. O. et al. , Phys. Rev. Lett. , 108 (2012) 033004) observed a new threshold behavior in the photodetachment of the potassium negative ion when the residual atom is left in the state. Unfortunately the resonance close to threshold made it more difficult to apply the semi-classical model that was developed to describe the threshold behavior. In this paper we present a study of the threshold behavior of the partial cross-section in the photodetachment of the sodium negative ion. The experiment was conducted using a collinear beams apparatus where the detection was performed using a resonance ionization scheme. We observe the same threshold behavior as in the previous experiment, but without any obfuscating resonance. The model derived in the previous paper is found to fit the observed cross-section up to 35 meV above threshold. The present experiment clearly demonstrates the threshold behaviour for the fundamental process of a free electron moving in the field of an atom with a large negative polarizability.