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Title: Excitation two-center interference and the orbital geometry in laser-induced nonsequential double ionization of diatomic molecules

Abstract

We address the influence of the molecular orbital geometry and of the molecular alignment with respect to the laser-field polarization on laser-induced nonsequential double ionization of diatomic molecules for different molecular species, namely N{sub 2} and Li{sub 2}. We focus on the recollision excitation with subsequent tunneling ionization (RESI) mechanism, in which the first electron, upon return, promotes the second electron to an excited state, from where it subsequently tunnels. We assume that both electrons are initially in the highest occupied molecular orbital (HOMO) and that the second electron is excited to the lowest unoccupied molecular orbital (LUMO). We show that the electron-momentum distributions exhibit interference maxima and minima due to the electron emission at spatially separated centers. We provide generalized analytical expressions for such maxima or minima, which take into account s-p mixing and the orbital geometry. The patterns caused by the two-center interference are sharpest for vanishing alignment angle and get washed out as this parameter increases. Apart from that, there exist features due to the geometry of the LUMO, which may be observed for a wide range of alignment angles. Such features manifest themselves as the suppression of probability density in specific momentum regions due to themore » shape of the LUMO wave function, or as an overall decrease in the RESI yield due to the presence of nodal planes.« less

Authors:
; ;  [1]
  1. Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)
Publication Date:
OSTI Identifier:
22051340
Resource Type:
Journal Article
Journal Name:
Physical Review. A
Additional Journal Information:
Journal Volume: 84; Journal Issue: 1; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1050-2947
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ELECTRON EMISSION; ELECTRONS; EXCITATION; EXCITED STATES; GEOMETRY; INTERFERENCE; IONIZATION; LASER RADIATION; LITHIUM SULFIDES; MOLECULAR ORBITAL METHOD; MOLECULES; POLARIZATION; TUNNEL EFFECT; WAVE FUNCTIONS

Citation Formats

Shaaran, T., Augstein, B. B., and Figueira de Morisson Faria, C. Excitation two-center interference and the orbital geometry in laser-induced nonsequential double ionization of diatomic molecules. United States: N. p., 2011. Web. doi:10.1103/PHYSREVA.84.013429.
Shaaran, T., Augstein, B. B., & Figueira de Morisson Faria, C. Excitation two-center interference and the orbital geometry in laser-induced nonsequential double ionization of diatomic molecules. United States. doi:10.1103/PHYSREVA.84.013429.
Shaaran, T., Augstein, B. B., and Figueira de Morisson Faria, C. Fri . "Excitation two-center interference and the orbital geometry in laser-induced nonsequential double ionization of diatomic molecules". United States. doi:10.1103/PHYSREVA.84.013429.
@article{osti_22051340,
title = {Excitation two-center interference and the orbital geometry in laser-induced nonsequential double ionization of diatomic molecules},
author = {Shaaran, T. and Augstein, B. B. and Figueira de Morisson Faria, C.},
abstractNote = {We address the influence of the molecular orbital geometry and of the molecular alignment with respect to the laser-field polarization on laser-induced nonsequential double ionization of diatomic molecules for different molecular species, namely N{sub 2} and Li{sub 2}. We focus on the recollision excitation with subsequent tunneling ionization (RESI) mechanism, in which the first electron, upon return, promotes the second electron to an excited state, from where it subsequently tunnels. We assume that both electrons are initially in the highest occupied molecular orbital (HOMO) and that the second electron is excited to the lowest unoccupied molecular orbital (LUMO). We show that the electron-momentum distributions exhibit interference maxima and minima due to the electron emission at spatially separated centers. We provide generalized analytical expressions for such maxima or minima, which take into account s-p mixing and the orbital geometry. The patterns caused by the two-center interference are sharpest for vanishing alignment angle and get washed out as this parameter increases. Apart from that, there exist features due to the geometry of the LUMO, which may be observed for a wide range of alignment angles. Such features manifest themselves as the suppression of probability density in specific momentum regions due to the shape of the LUMO wave function, or as an overall decrease in the RESI yield due to the presence of nodal planes.},
doi = {10.1103/PHYSREVA.84.013429},
journal = {Physical Review. A},
issn = {1050-2947},
number = 1,
volume = 84,
place = {United States},
year = {2011},
month = {7}
}