Berlin 2008 – wissenschaftliches Programm
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SYEC: Symposium Exact-exchange and hybrid functionals meet quasiparticle energy calculations
SYEC 2: Exact-exchange and hybrid functionals meet quasiparticle energy calculations II
SYEC 2.3: Vortrag
Donnerstag, 28. Februar 2008, 14:30–14:45, A 053
First-principles approach to Non-Collinear Magnetism: Towards Spin Dynamics — •Sangeeta Sharma1,2, J Kay Dewhurst3, Stefan Kurth2, Stefano Pittalis2, and E. K. U Gross2 — 11 Fritz Haber Institute of the Max Planck Society, Berlin, Germany. — 2Institut fur Theoretische Physik, Freie Universität Berlin, — 3School of Chemistry, University of Edinburgh, Edinburgh, UK
The exact treatment of exchange within the Kohn-Sham formulation of DFT has been one of the most interesting developments of ab-initio theory in recent years. Recently (PRL 98, 196405) we have extended this exact exchange method to describe non-collinear magnetism. The equations for the effective Kohn-Sham scalar potential and magnetic field are derived within the optimized effective potential framework. This is of particular importance for the future ab-initio approach to describe spin dynamics since the most widely used exchange-correlation (XC) approximations (like the LSDA/GGA) rely on the magnetization and XC magnetic field being made locally collinear, rendering these approximations improper for the study of spin-dynamics. This is a serious limitation. With an example of a magnetically frustrated Cr-monolayer and with the help of an accurate full-potential LAPW implementation of our newly derived equations we show that there is a strong local non-collinearity between the magnetization and exchange-correlation magnetic field making future time dependent extensions of this method highly suitable contenders for the ab-initio study of spin dynamics.