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O: Fachverband Oberflächenphysik
O 49: Ab-initio approaches to excitations in condensed matter II
O 49.6: Vortrag
Donnerstag, 26. März 2009, 11:45–12:00, SCH 251
Ab-initio Study of the Electronic and Optical Properties of MnO, FeO, CoO, and NiO — •Claudia Rödl, Frank Fuchs, Jürgen Furthmüller, and Friedhelm Bechstedt — Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
Although the electronic properties of MnO, FeO, CoO, and NiO have been studied for decades, the description of the one-particle excitation spectrum of these materials remains a challenge. Quasiparticle calculations using a perturbative treatment of Hedin’s GW approximation based on (semi)local approaches to exchange and correlation in the subjacent density-functional calculation fail to reproduce the experimental photoemission spectra.
For this reason, we use the non-local HSE03 exchange-correlation functional to obtain a reasonable starting point for a quasiparticle calculation within first-order perturbation theory and compare to results obtained within the computationally less expensive GGA+U scheme. The respective value for the on-site interaction U is determined by a fit to the more sophisticated HSE03+G0W0 band structure.
Furthermore, we examine the optical properties of these materials. Accounting for their antiferromagnetic ordering, we solve the spin-polarized Bethe-Salpeter equation (BSE) and calculate optical absorption spectra including excitonic and local-field effects.