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Title: Ionization Study of Isomeric Molecules in Strong-field Laser Pulses

Abstract

Through the use of the technique of time-of-flight mass spectroscopy, we obtain strong-field ionization yields for randomly oriented 1,2-dichloroethylene (1,2-DCE) (C 2H 2Cl 2) and 2-butene (C 4H 8). Here, we are interested in studying the effect of conformal structure in strong-field ionization and, in particular, the role of molecular polarity. That is, we can perform strong-field ionization studies in polar vs non-polar molecules that have the same chemical composition. Here, we report our findings through the ionization yields and the ratio (trans/cis) of each stereoisomer pair as a function of intensity.

Authors:
 [1];  [1];  [1];  [1]
  1. Kansas State Univ., Manhattan, KS (United States). Dept. of Physics
Publication Date:
Research Org.:
Kansas State Univ., Manhattan, KS (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1366468
Grant/Contract Number:
FG02-86ER13491
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 7; Journal ID: ISSN 2045-2322
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; atomic and molecular interactions with photons; chemical physics; electronic structure of atoms and molecules

Citation Formats

Zigo, Stefan, Le, Anh-Thu, Timilsina, Pratap, and Trallero-Herrero, Carlos A. Ionization Study of Isomeric Molecules in Strong-field Laser Pulses. United States: N. p., 2017. Web. doi:10.1038/srep42149.
Zigo, Stefan, Le, Anh-Thu, Timilsina, Pratap, & Trallero-Herrero, Carlos A. Ionization Study of Isomeric Molecules in Strong-field Laser Pulses. United States. doi:10.1038/srep42149.
Zigo, Stefan, Le, Anh-Thu, Timilsina, Pratap, and Trallero-Herrero, Carlos A. Fri . "Ionization Study of Isomeric Molecules in Strong-field Laser Pulses". United States. doi:10.1038/srep42149. https://www.osti.gov/servlets/purl/1366468.
@article{osti_1366468,
title = {Ionization Study of Isomeric Molecules in Strong-field Laser Pulses},
author = {Zigo, Stefan and Le, Anh-Thu and Timilsina, Pratap and Trallero-Herrero, Carlos A.},
abstractNote = {Through the use of the technique of time-of-flight mass spectroscopy, we obtain strong-field ionization yields for randomly oriented 1,2-dichloroethylene (1,2-DCE) (C2H2Cl2) and 2-butene (C4H8). Here, we are interested in studying the effect of conformal structure in strong-field ionization and, in particular, the role of molecular polarity. That is, we can perform strong-field ionization studies in polar vs non-polar molecules that have the same chemical composition. Here, we report our findings through the ionization yields and the ratio (trans/cis) of each stereoisomer pair as a function of intensity.},
doi = {10.1038/srep42149},
journal = {Scientific Reports},
number = ,
volume = 7,
place = {United States},
year = {Fri Feb 10 00:00:00 EST 2017},
month = {Fri Feb 10 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
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  • We have developed several calculation methods for the ionization of atoms and molecules by strong and ultrashort laser pulses, based on the numerical solution of the time dependent Schroedinger equation (TDSE) in the momentum space. We have performed calculations within the strong field approximation (Volkov) and using iterative and direct methods for solving the TDSE. The investigated molecules are H{sub 2}{sup +} and H{sub 2}O. In case of the ionization of diatomic molecules the interference effects in the ejected electron spectra due to the coherent addition of the waves associated to the electrons ejected from the vicinity of different nucleimore » were also analysed.« less
  • The strong-field ionization in a number of light homonuclear diatomic molecules (N{sub 2}, O{sub 2}, and H{sub 2}) irradiated by an intense laser field of low fundamental frequency {omega}<<I{sub p} is considered theoretically and studied numerically compared to their 'companion' atoms, having nearly identical ionization potential I{sub p}. The background applied strong-field approach is based on using the S-matrix formalism of conventional strong-field approximation supplemented by the standard linear combination of atomic orbitals and molecular orbitals method utilized for approximate analytical reproduction of the two-centered wave function of an initial molecular bound state. Accordingly, the ionization of a diatomic moleculemore » is described as a quantum-mechanical superposition (intramolecular interference) of contributions from ionization amplitudes corresponding to photoelectron emission from two atomic centers separated by equilibrium internuclear distance. Besides the bonding (or antibonding) symmetry of the highest occupied molecular orbitals (HOMO) corresponding to the outermost molecular valence shell, its spatial configuration and predominant orientation with respect to the internuclear axis and polarization of incident laser field also proved to be of substantial importance and, thus, are taken into equally detailed consideration. Moreover, wherever appropriate, the comparable contributions from other (inner) molecular valence shells of a larger binding energy (closest to that of HOMO, but of different bonding symmetry and spatial configuration) are additionally taken into account. The related results for calculated differential and/or integral molecular ionization rates, molecular photoelectron spectra, and angular distributions are fairly well consistent with available experimental data and, in particular, provide one with a transparent physical interpretation of the nature and origin of high suppression in ionization of the O{sub 2} molecule (as compared to its companion Xe atom) as well as no suppression in ionization of N{sub 2} molecules (as compared to its companion Ar atom)« less
  • V. I. Usachenko and S.-I. Chu [Phys. Rev. A, 71, 063410 (2005)] discuss the molecular strong-field approximation in the velocity gauge formulation and indicate that some of our earlier velocity gauge calculations are inaccurate. Here we comment on the results of Usachenko and Chu. First, we show that the molecular orbitals used by Usachenko and Chu do not have the correct symmetry, and second, that it is an oversimplification to describe the molecular orbitals in terms of just a single linear combination of two atomic orbitals. Finally, some values for the generalized Bessel function are given for comparison.
  • We acknowledge the criticism of the preceding Comment related to imperfect composition of our model 3{sigma}{sub g} molecular state [V. I. Usachenko and S.-I. Chu, Phys. Rev. A 71, 063410 (2005)]. However, we cannot agree with the authors suggesting this critique also as an irrefutable argument and evidence in support and justification of their opposite and incorrect (viz. inconsistent with relevant experiment) orientation dependence of N{sub 2} ionization rate calculated within the velocity gauge version of molecular strong-field approximation. We demonstrate that appropriately composed 3{sigma}{sub g} state (modified according to the Comment's critique) rather confirm the alternative calculation [A. Jaron-Becker,more » A. Becker, and F. H. M. Faisal, Phys. Rev. A 69, 023410 (2004)], which suggests correct orientation dependence of N{sub 2} ionization, contrary to respective results of the Comment's authors applying the same approach and procedure of 3{sigma}{sub g} composition.« less