Regensburg 2013 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 43: Correlated Electrons: Metal-Insulator Transition 2

TT 43.5: Vortrag

Mittwoch, 13. März 2013, 16:00–16:15, H19

DFT + DMFT calculations for epitaxially strained LaTiO₃ — •Krzysztof Dymkowski and Claude Ederer — Materials Theory, ETH Zurich, Switzerland

Even though bulk LaTiO₃ is a Mott insulator [1], metallic properties have been reported for thin films of LaTiO₃ grown on SrTiO₃ [2]. Such metallicity, can be due to a number of factors such as: electronic reconstruction at the interface, defects, or substrate-induced structural deformations. In order to identify the origin of the observed metallicity, we perform density functional theory plus dynamical mean field theory (DFT + DMFT) calculations for epitaxially strained LaTiO₃. First, we use standard DFT to accurately relax the structure under the epitaxial constraint, and we monitor hopping amplitudes and crystal-field splitting as a function of strain. Then, we calculate the electronic properties for the strained structures using DMFT. Based on our results we address the question whether the strain-induced structural modifications of LaTiO₃ are enough to change this insulator into a metal.
[1] E. Pavarini et al., Phys. Rev. Lett. 92, 176403 (2004)
F. J. Wong et al., Phys. Rev. B 81, 161101 (2010); C. He et al., Phys. Rev. B 86, 081401 (2012)