Berlin 2005 – wissenschaftliches Programm

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DS: Dünne Schichten

DS 21: FV-internes Symposium „Optische Spektroskopie von dünnen Schichten und Grenzfl
ächen"

DS 21.2: Hauptvortrag

Dienstag, 8. März 2005, 10:30–11:15, TU HS110

Ab-initio calculations of electronic and optical properties of surfaces — •Olivia Pulci — INFM, Department of Physics, University of Rome, Tor Vergata, Via della Ricerca Scientifica 1, I-00133 Rome, Italy

The microscopic study of complex systems has nowadays reached a high level of accuracy that allows for a deep understanding of the electronic excitations. Ab-initio description of experiments such as direct or inverse photoemission, optical absorption, electron energy loss, have become possible thanks to the huge progress in theory and the increased computational power. Charged excitations, as well as neutral excitations, can now be studied within the Many-Body Perturbation Theory based on the Green’s function formalism. Optical spectra can be calculated with inclusion of the electron hole interaction by solving the Bethe Salpeter equation (BSE) within the framework of Green’s function theory. Moreover, optical spectra can be nowadays also well described within the Time Dependent Density Functional Theory (TDDFT).

In this seminar we will present results for the electronic structure and reflectance anisotropy of diamond and silicon surfaces within DFT, GW, and BSE approach. Results for the optical spectrum of Si(111)2x1, calculated within the TDDFT approach will be also discussed.