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TT: Fachverband Tiefe Temperaturen

TT 19: CE: Metal-Insulator Transition 2

TT 19.4: Vortrag

Mittwoch, 24. März 2010, 10:15–10:30, H18

Structural transformations due to electronic correlations in paramagnetic KCuF₃ and LaMnO₃ — •Ivan Leonov¹, Dmitry Korotin², Nadia Binggeli³, Vladimir I. Anisimov², and Dieter Vollhardt¹ — ¹Theoretical Physics III, Center for Electronic Correlations and Magnetism, University of Augsburg, Germany — ²Institute of Metal Physics, Yekaterinburg, Russia — ³ICTP and INFM-CNR Democritos National Simulation Center, Trieste, Italy

We present a computational scheme for ab initio total-energy calculations of materials with strongly interacting electrons using a plane-wave basis set [1]. It combines ab initio band structure and dynamical mean-field theory and is implemented in terms of plane-wave pseudopotentials. The present approach allows us to investigate complex materials with strongly interacting electrons and is able to treat atomic displacements, and hence structural transformations, caused by electronic correlations. Results obtained for paramagnetic KCuF₃ and LaMnO₃, namely an equilibrium Jahn-Teller distortion and antiferro-orbital order agree well with experiment. The structural optimization performed for paramagnetic KCuF₃ yields the correct lattice constant, equilibrium Jahn-Teller distortion and tetragonal compression of the unit cell. The present approach is able to determine correlation-induced structural transformations, equilibrium atomic positions and lattice structure in both strongly and weakly correlated solids in their paramagnetic phases as well as in phases with long-range magnetic order.

[1] I. Leonov, N. Binggeli, Dm. Korotin, V. I. Anisimov, N. Stojić, and D. Vollhardt, Phys. Rev. Lett. 101, 096405 (2008).