Berlin 2015 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 71: Correlated Electrons: Poster Session

TT 71.70: Poster

Mittwoch, 18. März 2015, 15:00–18:00, Poster B

Metal-Insulator Transition and Lattice Instability of Paramagnetic V₂O₃ — •I. Leonov¹, V. I. Anisimov^2,3, and D. Vollhardt¹ — ¹Theoretical Physics III, Center for Electronic Correlations and Magnetism, University of Augsburg, Germany — ²Institute of Metal Physics, Yekaterinburg, Russia — ³Ural Federal University, Yekaterinburg, Russia

We determine the electronic structure and phase stability of paramagnetic V₂O₃ at the Mott-Hubbard metal-insulator phase transition, by employing a combination of ab initio methods for calculating band structures with dynamical mean-field theory [1]. To explore structural transformations as a function of pressure, we use the experimentally determined atomic positions for the metallic and insulating phases, respectively, and calculate the total energy as a function of volume. We find that the structural stability depends very sensitively on changes of the lattice volume. The structural transformation associated with the metal-insulator transition is found to occur upon a slight expansion of the lattice volume by ∼ 1.5 %, in agreement with experiment. Our results show that the structural change precedes the metal-insulator transition, implying a complex interplay between electronic and lattice degrees of freedom at the transition. Electronic correlations and full charge self-consistency are found to be crucial for a correct description of the properties of V₂O₃.

[1] I. Leonov, V. I. Anisimov, and D. Vollhardt, arXiv:1410.5399 (2014).