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Nonequilibrium Green's functions and atom-surface dynamics: Simple views from a simple model system

Vinas Boström, Emil LU ; Hopjan, Miroslav LU ; Kartsev, Alexey LU ; Verdozzi, Claudio LU and Almbladh, Carl-Olof LU (2016) 6th Interdisciplinary Conference on Progress in Non-Equilibrium Green's Functions, PNGF 2015 In Journal of Physics: Conference Series 696(1).
Abstract

We employ Non-equilibrium Green's functions (NEGF) to describe the real-time dynamics of an adsorbate-surface model system exposed to ultrafast laser pulses. For a finite number of electronic orbitals, the system is solved exactly and within different levels of approximation. Specifically i) the full exact quantum mechanical solution for electron and nuclear degrees of freedom is used to benchmark ii) the Ehrenfest approximation (EA) for the nuclei, with the electron dynamics still treated exactly. Then, using the EA, electronic correlations are treated with NEGF within iii) 2nd Born and with iv) a recently introduced hybrid scheme, which mixes 2nd Born self-energies with non-perturbative, local exchange- correlation potentials of... (More)

We employ Non-equilibrium Green's functions (NEGF) to describe the real-time dynamics of an adsorbate-surface model system exposed to ultrafast laser pulses. For a finite number of electronic orbitals, the system is solved exactly and within different levels of approximation. Specifically i) the full exact quantum mechanical solution for electron and nuclear degrees of freedom is used to benchmark ii) the Ehrenfest approximation (EA) for the nuclei, with the electron dynamics still treated exactly. Then, using the EA, electronic correlations are treated with NEGF within iii) 2nd Born and with iv) a recently introduced hybrid scheme, which mixes 2nd Born self-energies with non-perturbative, local exchange- correlation potentials of Density Functional Theory (DFT). Finally, the effect of a semi-infinite substrate is considered: we observe that a macroscopic number of de-excitation channels can hinder desorption. While very preliminary in character and based on a simple and rather specific model system, our results clearly illustrate the large potential of NEGF to investigate atomic desorption, and more generally, the non equilibrium dynamics of material surfaces subject to ultrafast laser fields.

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Please use this url to cite or link to this publication:
author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Physics: Conference Series
volume
696
issue
1
article number
012007
pages
10 pages
publisher
IOP Publishing
conference name
6th Interdisciplinary Conference on Progress in Non-Equilibrium Green's Functions, PNGF 2015
conference location
Lund, Sweden
conference dates
2015-08-17 - 2015-08-21
external identifiers
  • scopus:85043819931
ISSN
1742-6596
DOI
10.1088/1742-6596/696/1/012007
language
English
LU publication?
yes
id
7a599b93-bc32-46f4-8fd6-9a7b2b256626
date added to LUP
2019-05-16 11:09:47
date last changed
2022-01-31 20:06:18
@article{7a599b93-bc32-46f4-8fd6-9a7b2b256626,
  abstract     = {{<p>We employ Non-equilibrium Green's functions (NEGF) to describe the real-time dynamics of an adsorbate-surface model system exposed to ultrafast laser pulses. For a finite number of electronic orbitals, the system is solved exactly and within different levels of approximation. Specifically i) the full exact quantum mechanical solution for electron and nuclear degrees of freedom is used to benchmark ii) the Ehrenfest approximation (EA) for the nuclei, with the electron dynamics still treated exactly. Then, using the EA, electronic correlations are treated with NEGF within iii) 2nd Born and with iv) a recently introduced hybrid scheme, which mixes 2nd Born self-energies with non-perturbative, local exchange- correlation potentials of Density Functional Theory (DFT). Finally, the effect of a semi-infinite substrate is considered: we observe that a macroscopic number of de-excitation channels can hinder desorption. While very preliminary in character and based on a simple and rather specific model system, our results clearly illustrate the large potential of NEGF to investigate atomic desorption, and more generally, the non equilibrium dynamics of material surfaces subject to ultrafast laser fields.</p>}},
  author       = {{Vinas Boström, Emil and Hopjan, Miroslav and Kartsev, Alexey and Verdozzi, Claudio and Almbladh, Carl-Olof}},
  issn         = {{1742-6596}},
  language     = {{eng}},
  month        = {{04}},
  number       = {{1}},
  publisher    = {{IOP Publishing}},
  series       = {{Journal of Physics: Conference Series}},
  title        = {{Nonequilibrium Green's functions and atom-surface dynamics: Simple views from a simple model system}},
  url          = {{http://dx.doi.org/10.1088/1742-6596/696/1/012007}},
  doi          = {{10.1088/1742-6596/696/1/012007}},
  volume       = {{696}},
  year         = {{2016}},
}