Calendar of Physics Talks Vienna

Electronic-structure calculations for correlated materials: Combining FLAPW with DMFT and its application to the Pnictides
Speaker:Dr. Markus Aichhorn (École Polytechnique)
Abstract:During the last decades Density Functional Theory has proven to be a very powerful method for the prediction of physical properties of solid-state materials. Nevertheless, due to the necessary approximations to the unknown exchange-correlation potential, this theory fails to predict the properties of the very interesting class of materials with strong electron-electron interactions. One way to overcome this limitation is the supplementary use of Dynamical Mean-Field Theory to treat the strong interactions. In this talk, I will report on a new implementation of the DFT+DMFT scheme in the framework of a full-potential plane wave method, the Wien2K package. Its advantage is the high accuracy compared to other methods commonly used for these kind of calculations. A very intriguing physical problem, where this method can give an answer, is the question about the degree of correlations in the newly-discovered Pnictide superconductors. Our results for LaFeAsO, one of the parent compounds of the '1111' family, show that these materials should be regarded as moderately correlated metals with an effective mass of around 1.8. We also address the discrepancies between previous calculations on that compound, and discuss the importance of a reasonable choice of interaction parameters for these calculations.
Date: Tue, 08.09.2009
Time: 15:00
Duration: 60 min
Location:TU Wien, Wiedner Hauptstrasse 8-10, Rote Ber, 138B (7. Stock)