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

Model photodetachment with two continua

Andrzej Raczyński, Jarosław Zaremba

Published Feb 14, 1993• 2 citations
Publisher

Abstract

Non-perturbative, exact, analytical photodetachment spectra for a model negative ion including a single bound state and two continua are calculated with continuum-continuum transitions taken into account. Asymmetric two-peak structures of significant widths are shown to be the typical spectra both for l=1 and for l=2 photoelectrons. The population trapping in the initial state is demonstrated as due to a creation of a bound state of the dressed system.

DOI
10.1088/0953-4075/26/3/013

Related papers

Threshold effects and photoelectron spectra in model-system descriptions of photodetachment

Stanley L. Haan, P. A. Polstra, W. H. Schotanus +1 more

Near-threshold single-photon photodetachment processes are considered for simple model systems representing negative ions exposed to monochromatic radiation. The model systems considered feature an initial discrete state, the photoelectron continuum, and in some cases an excited or autodetaching discrete state. Population trapping through the formation of a bound dressed state and the photoelectron spectra are examined. Two photoelectron spectra are defined : a primary spectrum which results from decay while the laser interaction is on and a secondary spectrum which results from the destabilization of the bound dressed state if the interaction is turned off again. Careful attention is given to the passage of the poles of the Green's operator through the low-energy boundary of a continuum, and it is concluded that such poles move nonmonotonically through the boundary of an s-wave continuum, but monotonically through the boundary of a p-wave or higher-l-wave continuum. Two example systems, one featuring a single discrete state and an s-wave continuum and one featuring two discrete states and a p-wave continuum, are considered in detail.

Physical Review A•Nov 1, 1992•2 citations

Population trapping in continuum-continuum transitions

Zofia Białynicka-Birula

An exactly soluble model is used to describe transitions, induced by two strong laser beams, proceeding from the initial discrete state to the continuum via two channels. In the first channel the transition occurs via an intermediate, near-resonant discrete state located close to the continuum edge. In the second channel the intermediate state belongs to the continuum. Population trapping occurs due to an interference between the two channels. The model can be used to describe the photodetachment of electrons from negative ions or the photodissociation of molecules.

Journal of Physics B Atomic and Molecular Physics•Dec 14, 1983•13 citations

Threshold effects in photodetachment to a structured continuum

Andrzej Raczyński, Jarosław Zaremba

Near-threshold photodetachment in strong laser fields has been discussed in the case of the presence of an autoionizinglike state in the ionic continuum. The role of a real negative pole of the propagator is stressed. The corresponding terms in transition amplitudes give rise to a new structure of the photoelectron spectrum and to the population trapping.

Physical Review A•Aug 1, 1989•10 citations

An investigation of model above-threshold photodetachment spectra

Andrzej Raczyński, Jarosław Zaremba

A model photodetachment is considered in a non-perturbative approach which takes into account an infinite number of virtual photon and electron states. Closed analytical formulae for the photoelectron spectrum are obtained which result from some properties of particular infinite band matrices. The formulae give account of the most characteristic features of the above-threshold detachment. A numerical example is given.

Journal of Physics B Atomic Molecular and Optical Physics•Feb 14, 1996•4 citations

Photodetachment spectroscopy of quasibound states of the negative ion of lanthanum

C. W. Walter, N. D. Gibson, N. B. Lyman +1 more

The negative ion of lanthanum, $\mathrm{L}{\mathrm{a}}^{\text{--}}$, has one of the richest bound state spectra observed for an atomic negative ion and has been proposed as a promising candidate for laser-cooling applications. In the present experiments, $\mathrm{L}{\mathrm{a}}^{\text{--}}$ was investigated using tunable infrared photodetachment spectroscopy. The relative signal for neutral atom production was measured with a crossed ion-beam--laser-beam apparatus over the photon energy range 585--920 meV (2120--1350 nm) to probe the continuum region above the La neutral atom ground state. Eleven prominent peaks were observed in the $\mathrm{L}{\mathrm{a}}^{\text{--}}$ photodetachment cross section due to resonant excitation of quasibound transient negative ion states in the continuum, which subsequently autodetach. In addition, thresholds were observed for photodetachment from several bound states of $\mathrm{L}{\mathrm{a}}^{\text{--}}$ to both ground and excited states of La. The present results provide information on the excited state structure and dynamics of $\mathrm{L}{\mathrm{a}}^{\text{--}}$ that depend crucially on multielectron correlation effects.

arXiv:2010.01122•Physical Review A•Oct 13, 2020•3 citations

Two-frequency above threshold ionization with pulses

L. Wang, J. W. Haus, K. Rzazewski

We solve a model with one bound state and two continua.1 Two lasers are used to study the above threshold ionization process. The first laser couples the electron in a bound state to a continuum state. The photons are assumed to be energetic enough to promote the electron directly into the continuum far from the threshold; this avoids complications due to the Rydberg levels and the ponderomotive shifts of the threshold. The second laser mixes the electron wavefunction between two continuum states (C—C transitions); since we avoid the rotating wave approximation, multiple transitions between these continua are allowed. We find that the ionization rate is unaffected by the C—C transitions. Our model of hydrogenic atoms allows redistribution among the continua only during the ionization process and the photoelectron spectra exhibits peak suppression; i.e., the population is not the strongest at the energy of the ionization laser.

Annual Meeting Optical Society of America•Jan 1, 1989•0 citations
Non-perturbative, exact, analytical photodetachment spectra for a model negative ion including a single bound state and two continua are calculated with continuum-continuum transitions taken into account. Asymmetric two-peak structures of significant widths are shown to be the typical spectra both for l=1 and for l=2 photoelectrons. The population trapping in the initial state is demonstrated as due to a creation of a bound state of the dressed system.
Near-threshold single-photon photodetachment processes are considered for simple model systems representing negative ions exposed to monochromatic radiation. The model systems considered feature an initial discrete state, the photoelectron continuum, and in some cases an excited or autodetaching discrete state. Population trapping through the formation of a bound dressed state and the photoelectron spectra are examined. Two photoelectron spectra are defined : a primary spectrum which results from decay while the laser interaction is on and a secondary spectrum which results from the destabilization of the bound dressed state if the interaction is turned off again. Careful attention is given to the passage of the poles of the Green's operator through the low-energy boundary of a continuum, and it is concluded that such poles move nonmonotonically through the boundary of an s-wave continuum, but monotonically through the boundary of a p-wave or higher-l-wave continuum. Two example systems, one featuring a single discrete state and an s-wave continuum and one featuring two discrete states and a p-wave continuum, are considered in detail.
An exactly soluble model is used to describe transitions, induced by two strong laser beams, proceeding from the initial discrete state to the continuum via two channels. In the first channel the transition occurs via an intermediate, near-resonant discrete state located close to the continuum edge. In the second channel the intermediate state belongs to the continuum. Population trapping occurs due to an interference between the two channels. The model can be used to describe the photodetachment of electrons from negative ions or the photodissociation of molecules.
The negative ion of lanthanum, La–\mathrm{L}{\mathrm{a}}^{\text{--}}La–, has one of the richest bound state spectra observed for an atomic negative ion and has been proposed as a promising candidate for laser-cooling applications. In the present experiments, La–\mathrm{L}{\mathrm{a}}^{\text{--}}La– was investigated using tunable infrared photodetachment spectroscopy. The relative signal for neutral atom production was measured with a crossed ion-beam--laser-beam apparatus over the photon energy range 585--920 meV (2120--1350 nm) to probe the continuum region above the La neutral atom ground state. Eleven prominent peaks were observed in the La–\mathrm{L}{\mathrm{a}}^{\text{--}}La– photodetachment cross section due to resonant excitation of quasibound transient negative ion states in the continuum, which subsequently autodetach. In addition, thresholds were observed for photodetachment from several bound states of La–\mathrm{L}{\mathrm{a}}^{\text{--}}La– to both ground and excited states of La. The present results provide information on the excited state structure and dynamics of La–\mathrm{L}{\mathrm{a}}^{\text{--}}La– that depend crucially on multielectron correlation effects.
We solve a model with one bound state and two continua.1 Two lasers are used to study the above threshold ionization process. The first laser couples the electron in a bound state to a continuum state. The photons are assumed to be energetic enough to promote the electron directly into the continuum far from the threshold; this avoids complications due to the Rydberg levels and the ponderomotive shifts of the threshold. The second laser mixes the electron wavefunction between two continuum states (C—C transitions); since we avoid the rotating wave approximation, multiple transitions between these continua are allowed. We find that the ionization rate is unaffected by the C—C transitions. Our model of hydrogenic atoms allows redistribution among the continua only during the ionization process and the photoelectron spectra exhibits peak suppression; i.e., the population is not the strongest at the energy of the ionization laser.