Aufsatz in einer Fachzeitschrift
Alternative microscopic approach to the photoabsorption of small clusters
Details zur Publikation
Autor(inn)en: | Grabowski, S.; Garcia, M.; Bennemann, K. |
Verlag: | WORLD SCIENTIFIC PUBL CO PTE LTD |
Publikationsjahr: | 1996 |
Zeitschrift: | Modern Physics Letters B |
Seitenbereich: | 241-268 |
Jahrgang/Band : | 10 |
Erste Seite: | 241 |
Letzte Seite: | 268 |
Seitenumfang: | 28 |
ISSN: | 0217-9849 |
eISSN: | 1793-6640 |
Zusammenfassung, Abstract
A Wannier-type electronic theory to calculate self-consistently the photoabsorption spectra of small clusters is presented. This approach, that applies to systems with mainly localized electrons, permits a detailed analysis of the dependence of the absorption cross-section on atomic structure and cluster size. In addition the approach also allows a transparent identification of the optical excitations contributing to the different absorption peaks. By applying this theory to neutral and ionized mercury clusters one finds that both exciton- and plasmon-like excitations are present in the absorption spectra. Furthermore the dependence of the optical response on short- and long-range Coulomb interactions, on structural changes of the system and on the specific bonding character of the cluster is studied. It is demonstrated that the broadening of the collective excitations in small clusters with localized electrons depends sensitively on the atomic structure, in particular at the surface. The limitations of this theory and its extension to systems having also delocalized electrons, like noble- and transition-metal clusters are discussed.
A Wannier-type electronic theory to calculate self-consistently the photoabsorption spectra of small clusters is presented. This approach, that applies to systems with mainly localized electrons, permits a detailed analysis of the dependence of the absorption cross-section on atomic structure and cluster size. In addition the approach also allows a transparent identification of the optical excitations contributing to the different absorption peaks. By applying this theory to neutral and ionized mercury clusters one finds that both exciton- and plasmon-like excitations are present in the absorption spectra. Furthermore the dependence of the optical response on short- and long-range Coulomb interactions, on structural changes of the system and on the specific bonding character of the cluster is studied. It is demonstrated that the broadening of the collective excitations in small clusters with localized electrons depends sensitively on the atomic structure, in particular at the surface. The limitations of this theory and its extension to systems having also delocalized electrons, like noble- and transition-metal clusters are discussed.
