Electron dynamics following photoionization: decoherence due to the nuclear-wave-packet width
File(s)
Published version
Author(s)
Vacher, M
Steinberg, L
Jenkins, AJ
Bearpark, MJ
Robb, MA
Type
Journal Article
Abstract
The advent of attosecond techniques opens up the possibility to observe experimentally electron dynamics following ionization of molecules. Theoretical studies of pure electron dynamics at single fixed nuclear geometries in molecules have demonstrated oscillatory charge migration at a well-defined frequency but often neglecting the natural width of the nuclear wave packet. The effect on electron dynamics of the spatial delocalization of the nuclei is an outstanding question. Here, we show how the inherent distribution of nuclear geometries leads to dephasing. Using a simple analytical model, we demonstrate that the conditions for a long-lived electronic coherence are a narrow nuclear wave packet and almost parallel potential-energy surfaces of the states involved. We demonstrate with numerical simulations the decoherence of electron dynamics for two real molecular systems (paraxylene and polycyclic norbornadiene), which exhibit different decoherence time scales. To represent the quantum distribution of geometries of the nuclear wave packet, the Wigner distribution function is used. The electron dynamics decoherence result has significant implications for the interpretation of attosecond spectroscopy experiments since one no longer expects long-lived oscillations.
Date Issued
2015-10-20
Date Acceptance
2015-10-20
Citation
Physical Review A, 2015, 92 (4), pp.1-6
ISSN
1094-1622
Publisher
American Physical Society
Start Page
1
End Page
6
Journal / Book Title
Physical Review A
Volume
92
Issue
4
Copyright Statement
© 2015 American Physical Society
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://journals.aps.org/pra/abstract/10.1103/PhysRevA.92.040502
Grant Number
EP/I032517/1
Subjects
Science & Technology
Physical Sciences
Optics
Physics, Atomic, Molecular & Chemical
Physics
ULTRAFAST CHARGE MIGRATION
ATTOSECOND PULSES
REAL-TIME
SPECTROSCOPY
General Physics
01 Mathematical Sciences
02 Physical Sciences
03 Chemical Sciences
Publication Status
Published
Article Number
040502
Date Publish Online
2015-10-20