Dresden 2011 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 7: Computational Materials Modelling II

MM 7.3: Talk

Monday, March 14, 2011, 15:00–15:15, IFW B

Treatment of strongly correlated systems within the framework of reduced density matrix functional theory — •Sangeeta Sharma, J. K. Dewhurst, and E. K. U. Gross — Max-Planck-Institut für Mikrostrukturphysik, D - 06120 Halle

One of the most dramatic failures of the usual local density approximation or generalized gradient type approximations to the exchange-correlation functional of density functional theory is the incorrect prediction of a metallic ground state for the strongly correlated Mott insulators, of which transition metal oxides (TMOs) may be considered as prototypical.

In the present work we extend reduced density matrix functional theory (RDMFT) to the case of solid-state systems and introduce a new functional for their accurate treatment [1]. Furthermore, a method for calculating the spectrum of extended solids within RDMFT is presented. An application of this method to the strongly correlated TMOs demonstrates that (i) an insulating state is found in the absence of magnetic order and, in addition, (ii) the interplay between the charge transfer and Mott-Hubbard correlation is correctly described. In this respect we find that while NiO has a strong charge transfer character to the electronic gap, with substantial hybridization between $t_{2g}$ and oxygen-$p$ states in the lower Hubbard band, for MnO this is almost entirely absent [2]. References 1. S. Sharma, J. K. Dewhurst, N. N. Lathiotakis and E. K. U. Gross Phys. Rev. B 78, 201103 Rapid Comm. (2008) 2. S. Sharma, S. Shallcross, J. K. Dewhurst and E. K. U. Gross cond-mat/0912.1118