Polaron Mass and Electron-Phonon Correlations in the Holstein Model
The Holstein Molecular Crystal Model is investigated by a strong coupling perturbative method which, unlike the standard Lang-Firsov approach, accounts for retardation effects due to the spreading of the p...
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| Format: | Article |
| Language: | English |
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Wiley
2010-01-01
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| Series: | Advances in Condensed Matter Physics |
| Online Access: | http://dx.doi.org/10.1155/2010/815917 |
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| _version_ | 1832545450294509568 |
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| author | Marco Zoli |
| author_facet | Marco Zoli |
| author_sort | Marco Zoli |
| collection | DOAJ |
| description | The Holstein
Molecular Crystal Model is investigated by a
strong coupling perturbative method which,
unlike the standard Lang-Firsov approach,
accounts for retardation effects due to the
spreading of the polaron size. The effective
mass is calculated to the second perturbative
order in any lattice dimensionality for a broad
range of (anti)adiabatic regimes and
electron-phonon couplings. The crossover from a
large to a small polaron state is found in all
dimensionalities for adiabatic and intermediate
adiabatic regimes. The phonon dispersion largely
smoothes such crossover which
is signalled by polaron mass enhancement and on-site localization
of the correlation function. The notion of self-trapping together
with the conditions for the existence of light polarons, mainly in
two- and three-dimensions, is discussed. By the imaginary time
path integral formalism I show how nonlocal electron-phonon
correlations, due to dispersive phonons, renormalize downwards the
e-ph coupling justifying the possibility for
light and essentially small 2D Holstein polarons. |
| format | Article |
| id | doaj-art-878bf914a3b7463dae2945381662451b |
| institution | Kabale University |
| issn | 1687-8108 1687-8124 |
| language | English |
| publishDate | 2010-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advances in Condensed Matter Physics |
| spelling | doaj-art-878bf914a3b7463dae2945381662451b2025-02-03T07:25:52ZengWileyAdvances in Condensed Matter Physics1687-81081687-81242010-01-01201010.1155/2010/815917815917Polaron Mass and Electron-Phonon Correlations in the Holstein ModelMarco Zoli0Dipartimento di Fisica, Universitá di Camerino, 62032 Camerino, ItalyThe Holstein Molecular Crystal Model is investigated by a strong coupling perturbative method which, unlike the standard Lang-Firsov approach, accounts for retardation effects due to the spreading of the polaron size. The effective mass is calculated to the second perturbative order in any lattice dimensionality for a broad range of (anti)adiabatic regimes and electron-phonon couplings. The crossover from a large to a small polaron state is found in all dimensionalities for adiabatic and intermediate adiabatic regimes. The phonon dispersion largely smoothes such crossover which is signalled by polaron mass enhancement and on-site localization of the correlation function. The notion of self-trapping together with the conditions for the existence of light polarons, mainly in two- and three-dimensions, is discussed. By the imaginary time path integral formalism I show how nonlocal electron-phonon correlations, due to dispersive phonons, renormalize downwards the e-ph coupling justifying the possibility for light and essentially small 2D Holstein polarons.http://dx.doi.org/10.1155/2010/815917 |
| spellingShingle | Marco Zoli Polaron Mass and Electron-Phonon Correlations in the Holstein Model Advances in Condensed Matter Physics |
| title | Polaron Mass and Electron-Phonon Correlations in the Holstein Model |
| title_full | Polaron Mass and Electron-Phonon Correlations in the Holstein Model |
| title_fullStr | Polaron Mass and Electron-Phonon Correlations in the Holstein Model |
| title_full_unstemmed | Polaron Mass and Electron-Phonon Correlations in the Holstein Model |
| title_short | Polaron Mass and Electron-Phonon Correlations in the Holstein Model |
| title_sort | polaron mass and electron phonon correlations in the holstein model |
| url | http://dx.doi.org/10.1155/2010/815917 |
| work_keys_str_mv | AT marcozoli polaronmassandelectronphononcorrelationsintheholsteinmodel |