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O: Oberflächenphysik

O 13: Postersitzung (Adsorption auf Oberfl
ächen, Oberfl
ächenreaktionen, Elektronische Struktur, Epitaxie und Wachstum, Halbleiteroberfl
ächen und Grenzfl
ächen, Oxide und Isolatoren)

O 13.29: Poster

Montag, 26. März 2001, 19:00–22:00, Foyer zu B

The Electronic Structure of Cu Revisited: Experimental Self-Energy Effects in Unoccupied and Occupied Bands — •V. N. Strocov^1,2, P.O. Nilsson², P. Blaha³, G. Nicolay⁴, S. Hüfner⁴, and R. Claessen¹ — ¹Experimentalphysik II, Universität Augsburg, D-86135 Augsburg — ²Chalmers University of Technology, SE-41296 Göteborg, Sweden — ³Technische Universität Wien, A-1060 Wien, Austria — ⁴Universität des Saarlandes, D-66041 Saarbrücken

The excited-state self-energy effects in the electronic structure of Cu are determined by comparison of experimental excitation spectra with the density-functional theory. The unoccupied bands were mapped resolved in the three-dimensional wavevector k by Very-Low Energy Electron Diffraction, taking into advantage the single-state and k-resolving nature of this technique. These bands were further used to control k in photoemission mapping of the occupied bands [V. N. Strocov et al., PRL 81 4943 (1998)]. The density-functional calculations employed a full-potential LAPW method including spin-orbit coupling. Despite of the less-correlated nature of Cu, through the unoccupied and occupied we have found significant self-energy corrections with a distinct band- and k-dependence connected to the spatial localization of the one-electron wavefunctions: its larger weight in the core region correlated with larger self-energy repulsion from the Fermi level. We elucidate the essential physics of this effect by introdicing a wavefunction-weighted electron density and generalizing the electron gas exchange-correlation behavior. Further analysis using first-principles many-body calculations is required.