dc.contributor.author
Säkkinen, Niko
dc.contributor.author
Peng, Yang
dc.contributor.author
Appel, Heiko
dc.contributor.author
Leeuwen, Robert van
dc.date.accessioned
2018-06-08T03:35:18Z
dc.date.available
2016-03-18T11:06:04.651Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/15500
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-19688
dc.description.abstract
We study ground-state properties of a two-site, two-electron Holstein model
describing two molecules coupled indirectly via electron-phonon interaction by
using both exact diagonalization and self-consistent diagrammatic many-body
perturbation theory. The Hartree and self-consistent Born approximations used
in the present work are studied at different levels of self-consistency. The
governing equations are shown to exhibit multiple solutions when the electron-
phonon interaction is sufficiently strong, whereas at smaller interactions,
only a single solution is found. The additional solutions at larger electron-
phonon couplings correspond to symmetry-broken states with inhomogeneous
electron densities. A comparison to exact results indicates that this symmetry
breaking is strongly correlated with the formation of a bipolaron state in
which the two electrons prefer to reside on the same molecule. The results
further show that the Hartree and partially self-consistent Born solutions
obtained by enforcing symmetry do not compare well with exact energetics,
while the fully self-consistent Born approximation improves the qualitative
and quantitative agreement with exact results in the same symmetric case. This
together with a presented natural occupation number analysis supports the
conclusion that the fully self-consistent approximation describes partially
the bipolaron crossover. These results contribute to better understanding how
these approximations cope with the strong localizing effect of the electron-
phonon interaction.
en
dc.rights.uri
http://publishing.aip.org/authors/web-posting-guidelines
dc.subject.ddc
500 Naturwissenschaften und Mathematik::530 Physik
dc.subject.ddc
500 Naturwissenschaften und Mathematik::540 Chemie
dc.title
Many-body Green’s function theory for electron-phonon interactions
dc.type
Wissenschaftlicher Artikel
dcterms.bibliographicCitation
The Journal of Chemical Physics. - 143 (2015), 23, Artikel Nr. 234101
dc.title.subtitle
Ground state properties of the Holstein dimer
dcterms.bibliographicCitation.doi
10.1063/1.4936142
dcterms.bibliographicCitation.url
http://dx.doi.org/10.1063/1.4936142
refubium.affiliation
Physik
de
refubium.mycore.fudocsId
FUDOCS_document_000000024190
refubium.resourceType.isindependentpub
no
refubium.mycore.derivateId
FUDOCS_derivate_000000006133
dcterms.accessRights.openaire
open access