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O: Fachverband Oberflächenphysik
O 70: Focussed Session: Frontiers of Electronic Structure Theory - Non-equilibrium Phenomena at the Nano-scale VI
O 70.5: Vortrag
Donnerstag, 3. April 2014, 11:45–12:00, TRE Ma
Electron-Energy Loss and Inelastic X-ray Scattering of CuO from First Principles — •Claudia Rödl, Francesco Sottile, Matteo Gatti, and Lucia Reining — Laboratoire des Solides Irradiés, Ecole Polytechnique, CNRS, CEA-DSM, 91128 Palaiseau cedex, France and European Theoretical Spectroscopy Facility (ETSF)
Even though the strongly correlated transition-metal oxide CuO has many fields of application (potential absorber material in photovoltaic devices, pigment in glass and ceramics, building block of cuprate superconductors,...), surprisingly little is known about its electronic excitations from a theoretical point of view. The band gap and all electronic excitations in its vicinity are governed by the intricate interplay between itinerant O 2p and localized Cu 3d electrons. Complex many-body effects, that are still not well understood nowadays, determine the screening of the electron-electron interaction.
Electron-energy loss and inelastic x-ray scattering experiments yield direct access to the wave-vector- and frequency-dependent loss function −Im εGG′−1(q,ω), and, hence, to the screened Coulomb interaction W. We use time-dependent density-functional theory (TDDFT) to calculate the loss spectrum of CuO and discuss the occurring d-d and plasmon excitations. This allows us, by comparing theory and experiment, to assess the quality of the screened Coulomb interaction which is a key quantity for many-body approaches, for instance, GW and Bethe-Salpeter calculations.