Münster 1997 – wissenschaftliches Programm

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M: Metallphysik

M 22: Elektronische Strukturen und Eigenschaften II

M 22.3: Vortrag

Freitag, 21. März 1997, 10:10–10:30, S 6

Band-structure and many-body effects in the dynamical response of simple metals — •A. Fleszar¹, A.G. Eguiluz^2,3, B.C. Larson³, and J.Z. Tischler³ — ¹Institut für Theoretische Physik, Universität Würzburg, 97094 Würzburg — ²Department of Physics and Astronomy, The University of Tennessee, Knoxville, TN 37996-1200 — ³Solid State Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6030

A report will be given on recent progress in the theoretical and experimental determination of the dynamical-structure factor S(q,ω) of simple metals. A comparison of the ab initio calculations based on the LDA band structure of simple metals with high-resolution inelastic x-ray scattering experiments on Al leads to the following conclusions: a) the band structure of simple metals is necessary not only for the explanation of sharp lattice-induced structures, but also for the overall shape of the experimental spectra; b) sharp structures found in calculations at excitation energies above 40 eV are strongly damped in experimental measurements, possibly indicating the importance of lifetime effects for electron-hole excitations at these energies; c) the many-body local-field factor G(q,ω) obtained from measured spectra using ab initio calculations is larger than predicted by most electron-gas theories for large-q, and almost real and ω-independent for intermediate values of q.