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

Chinese Physics

Photoionization properties of an atom with two autoionizing states

Hong Guo, Gao‐xiang Li, Jin-sheng Peng

Published Jun 19, 2002• 0 citations
Publisher

Abstract

We have investigated the photoionization properties of an atom with a ladder coupling scheme involving two autoionizing states coupled to each other. The effects of the coherent coupling between two autoionizing states and between the low-lying autoionizing state and the continuum on the ionization yield are discussed. The conditions leading to atomic coherent population trapping and the coherent population trapping states are given explicitly.

DOI
10.1088/1009-1963/11/7/309

Related papers

Photoionization properties of an atom with two autoionizing states

郭红, 李高翔, 彭金生

We have investigated the photoionization properties of an atom with a ladder coupling scheme involving two autoionizing states coupled to each other.The effects of the coherent coupling between two autoionizing states and between the low-lying autoionizing state and the continuum on the ionization yield are discussed.The conditions leading to atomic coherent population trapping and the coherent population trapping states are given explicitly.

中国物理B：英文版•Jun 12, 2005•0 citations

Coherent Population Trapping in a Λ-Configuration Photoionization System in the Presence of an Autoionizing State

Gao‐xiang Li, PENG JIN-SHENG, Peng Zhou

We investigate the atomic coherent population trapping in the system of two-mode quantized field interacting with a Λ-configuration atom with two lower bound states, one autoionizing state and a flat atomic continuum. The states of the field which traps the atom in its two lower bound states are given and the influence of the field induced continuum structure is examined.

Communications in Theoretical Physics•Dec 15, 1997•0 citations

Effects of coherent coupling of autoionizing states on multiphoton ionization

Natalia E. Karapanagioti, Dimitrios Charalambidis, Cornelis J. G. J. Uiterwaal +4 more

We present the experimental and theoretical investigation of the effects of the strong electromagnetic coupling of two autoionizing states (AIS's) on the photoionization properties of an atomic system. These effects are observed by probing the ladder system from the ground state of the atom through a weak two-photon transition to the region of the lower AIS. The experimental observation of the modification of the total ionization and partial photoelectron spectra at different wavelengths of the coupling and probe lasers are accurately reproduced by a theoretical analysis which uses a density-matrix approach. Both theory and experiment indicate a strong inhibition of the ionization of the system in the case when both lasers are resonant with the two atomic transitions, while displaying a rapidly varying asymmetry induced as the detuning between the two states and the fields increases. In the extreme case of a large detuning, two separate structures appear as distinct total ionization and photoelectron peaks. The above findings combined with the full theoretical treatment indicate that the phenomena observed are an experimental demonstration of ac Stark splitting between two AIS's. \textcopyright{} 1996 The American Physical Society.

Physical Review A•Apr 1, 1996•59 citations

Observation of Autoionization Suppression through Coherent Population Trapping

Natalia E. Karapanagioti, O. Faucher, Yun Shao +3 more

The strong electromagnetic coupling of two autoionizing states is experimentally investigated for the first time and is shown to lead to coherent population trapping resulting in a reduction of the ionization. The experimental observation of partial stabilization is supported by a theoretical analysis which reproduces the modification of the Fano profiles and indicates that the strong coupling of the two states leads to the trapping of the population in the ground state of the atom.

Physical Review Letters•Mar 27, 1995•72 citations

Effects of laser phases on photoionization and coherent population trapping in a two-channel ionization system

Gao‐xiang Li, Jin-sheng Peng, Peng Zhou

We have studied the effects of laser phases on photoionization rate and atomic coherent population trapping in a two-channel ionization system. A dressed-state analysis is given to explain the appearance of phase-dependent atomic coherent population trapping.

Journal of Modern Optics•Mar 1, 1997•5 citations

One- and two-photon ionization

de Meijere, Jacob Louis Frederik

Detailed descriptions of one- and two-photon ionization are presented. We go beyond conventional perturbation theory to investigate the dynamics of both processes for a broad range of field intensities. The general theory of unstable decaying states is applied to the problem of one-photon ionization (the photoeffect). It is found that a non-trivial dependence of the transition dipole moment on the continuum state energy can lead to corrections to exponential decay, and even oscillations in the bound state population. As examples we consider the photoionization of hydrogen and atoms with autoionizing states. Only in the absence of autoionizing states corrections to exponential decay remain inconsequential for any experimentally relevant intensity. Our description of two-photon ionization is formulated in the Heisenberg picture. Besides the usual two-level atom projection operators we introduce explicitly the operators referring to the atomic continuum. By eliminating from the equations of motion the terms related to the electromagnetic self field as well as the terms referring to the continuum, transverse and longitudinal damping corresponding to spontaneous emission and photoionization is obtained. The use of field correlation functions allows us to account for the partial coherence of the applied field. We develop a technique to extract from the equations of motion a unique two-photon ionization rate. Such a characterization of the ionization process is not only instructive because of its simplicity, it is also in many cases completely satisfactory. The resulting general expression for the two-photon ionization rate is the central result of our treatment. From it we recover several familiar results in different limiting cases. In addition, our general rate expression provides the first description of the complete hierarchy of saturation effects that one should expect. We present a number of examples where we calculate the two-photon ionization rate as a function of the detuning, and where we emphasize the saturation and field correlation effects.

•Jan 1, 2016•0 citations
We have investigated the photoionization properties of an atom with a ladder coupling scheme involving two autoionizing states coupled to each other. The effects of the coherent coupling between two autoionizing states and between the low-lying autoionizing state and the continuum on the ionization yield are discussed. The conditions leading to atomic coherent population trapping and the coherent population trapping states are given explicitly.
We present the experimental and theoretical investigation of the effects of the strong electromagnetic coupling of two autoionizing states (AIS's) on the photoionization properties of an atomic system. These effects are observed by probing the ladder system from the ground state of the atom through a weak two-photon transition to the region of the lower AIS. The experimental observation of the modification of the total ionization and partial photoelectron spectra at different wavelengths of the coupling and probe lasers are accurately reproduced by a theoretical analysis which uses a density-matrix approach. Both theory and experiment indicate a strong inhibition of the ionization of the system in the case when both lasers are resonant with the two atomic transitions, while displaying a rapidly varying asymmetry induced as the detuning between the two states and the fields increases. In the extreme case of a large detuning, two separate structures appear as distinct total ionization and photoelectron peaks. The above findings combined with the full theoretical treatment indicate that the phenomena observed are an experimental demonstration of ac Stark splitting between two AIS's. \textcopyright{} 1996 The American Physical Society.
Detailed descriptions of one- and two-photon ionization are presented. We go beyond conventional perturbation theory to investigate the dynamics of both processes for a broad range of field intensities. The general theory of unstable decaying states is applied to the problem of one-photon ionization (the photoeffect). It is found that a non-trivial dependence of the transition dipole moment on the continuum state energy can lead to corrections to exponential decay, and even oscillations in the bound state population. As examples we consider the photoionization of hydrogen and atoms with autoionizing states. Only in the absence of autoionizing states corrections to exponential decay remain inconsequential for any experimentally relevant intensity. Our description of two-photon ionization is formulated in the Heisenberg picture. Besides the usual two-level atom projection operators we introduce explicitly the operators referring to the atomic continuum. By eliminating from the equations of motion the terms related to the electromagnetic self field as well as the terms referring to the continuum, transverse and longitudinal damping corresponding to spontaneous emission and photoionization is obtained. The use of field correlation functions allows us to account for the partial coherence of the applied field. We develop a technique to extract from the equations of motion a unique two-photon ionization rate. Such a characterization of the ionization process is not only instructive because of its simplicity, it is also in many cases completely satisfactory. The resulting general expression for the two-photon ionization rate is the central result of our treatment. From it we recover several familiar results in different limiting cases. In addition, our general rate expression provides the first description of the complete hierarchy of saturation effects that one should expect. We present a number of examples where we calculate the two-photon ionization rate as a function of the detuning, and where we emphasize the saturation and field correlation effects.