Regensburg 2010 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 46: Density functional theory and beyond for real materials I

O 46.5: Vortrag

Mittwoch, 24. März 2010, 11:30–11:45, H34

A strong correlation study: the paradigmatic case of V₂O₃ — •Federico Iori — Lsi - Ecole Polytechnique,Cnrs -Cea-Iramis Palaiseau, France

Aim of our work is to study through an ab initio theoretical approach the paramagnetic metallic (PM) and insulating (PI) phase of V₂O₃ in order to understand better the metal-insulator phase transition of this system. It has been shown that at DFT level it’s not possible to describe properly the insulating paramagnetic phase because of a poor treatment of the strong electronic correlation for such systems with d- or f- incomplete shell within including many body effect such the ones arising from a direct photoemission spectroscopy. Hard x-ray inelastic x-ray scattering in the non resonant regime has indeed proven highly effective to measure low energy losses, especially dd excitations, when operating at high momentum transfer. The dynamical structure factor for PM and PI phase of the V₂O₃ has been thus evaluated through ab initio calculations of the loss function for large transferred momenta parallel and perpendicular to the xy plane. Experimental evindence shown in the energy region between 2-3 eV, non dipolar transitions which favor intraband excitations become increasingly allowed while the probing length q⁻¹ approaches typical d orbital spatial extension.