Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
O: Oberflächenphysik
O 33: Nanostrukturen II
O 33.12: Vortrag
Donnerstag, 27. März 2003, 17:45–18:00, FOE/ORG
Exchange and Correlation Effects in Small Jellium Clusters — •Patrick Rinke1,2, Rex Godby1 und Pablo P.García-González3 — 1Department of Physics, University of York — 2now at: Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin — 3Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid
We present ab initio electronic structure calculations for small, spherical jellium clusters or quantum dots in the GW self-energy approach. In particular we analyse the effects of exchange and correlation, which give rise to image effects in these structures.
In recent years, GW (G: Green’s Function, W: Screened Coulomb Potential) has successfully been applied to calculate band structures of bulk materials and surfaces as well as properties of small molecules and clusters. We apply ab initio many-body perturbation theory (MBPT) in the GW approximation to solve the quasiparticle equation, using a space-time approach for the self-energy.
We analyse the structure of the self-energy operator in real-space including its non-locality and frequency dependence. Substantial changes (up to about 1 eV) in the quasiparticle energy spectrum are observed, which arise in part from physical effects inherently absent in other methods such as density-functional theory (DFT), in the usual approximations. The wave functions for unoccupied states near the vacuum level deviate considerably from eigenstates of the DFT system at similar energy.