Dresden 2009 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 6: Postersession Correlated Electrons: (General) Theory, Low-Dimensional Systems, Kondo Physics, Heavy Fermions, Quantum-Critical Phenomena
TT 6.12: Poster
Montag, 23. März 2009, 13:00–16:45, P1A
Structural relaxation due to electronic correlations in the paramagnetic insulator KCuF3 — •Ivan Leonov1, Nadia Binggeli2,3, Dmitry Korotin4, Vladimir I. Anisimov4, Natasa Stojic5,3, and Dieter Vollhardt1 — 1Theoretical Physics III, Center for Electronic Correlations and Magnetism, University of Augsburg, D-86135 Augsburg, Germany — 2Abdus Salam International Center for Theoretical Physics, 34014 Trieste, Italy — 3INFM-CNR Democritos, 34014 Trieste, Italy — 4Institute of Metal Physics, 620219 Yekaterinburg GSP-170, Russia — 5International School for Advanced Studies, SISSA, 34014 Trieste, Italy
We present a computational scheme for the investigation of complex materials with strongly interacting electrons which is able to treat atomic displacements, and hence structural relaxation, caused by electronic correlations [1]. It combines ab initio band structure and dynamical mean-field theory and is implemented in terms of plane-wave pseudopotentials. Results obtained for paramagnetic KCuF3, namely an equilibrium Jahn-Teller distortion of 4.2% and antiferro-orbital ordering, agree well with experiment. The electronic correlations are also found to be responsible for a considerable enhancement of the orbital polarization. The GGA+DMFT scheme presented here opens the way for fully microscopic investigations of the structural properties of strongly correlated electron materials such as lattice instabilities observed at correlation induced metal-insulator transitions.
[1] I. Leonov, N. Binggeli, Dm. Korotin, V. I. Anisimov, N. Stojić, and D. Vollhardt, Phys. Rev. Lett. 101, 096405 (2008).