Regensburg 2004 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 32: Theoretische Modelierung von Materialien mit korrelierten Elektronen

TT 32.7: Vortrag

Freitag, 12. März 2004, 11:45–12:00, H18

Mott transition and suppression of orbital fluctuations in orthorhombic 3d¹ perovskites — •E. Pavarini¹, S. Biermann^2,3, A. Poteryaev⁴, A.I. Lichtenstein⁴, A. Georges³, and O.K. Andersen⁵ — ¹INFM and Dipartimento di Fisica "A.Volta", Pavia, Italy — ²Laboratoire de Physique des Solides, CNRS-UMR 8502, UPS Bat. 510, 91405 Orsay France — ³LPT-ENS CNRS-UMR 8549, 24 Rue Lhomond, 75231 Paris Cedex 05, France — ⁴NSRIM, UNSRIM, University of Nijmegen, NL-6525 ED Nijmegen, The Netherlands — ⁵Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany

Using the first-principles downfolding technique, a low-energy Hamiltonian is derived for several 3d¹ transition metal oxides. Electronic correlations are included by combining this approach with an implementation of dynamical mean-field theory appropriate for non-cubic systems. Good agreement with photoemission data is obtained. The interplay of correlation effects and structural distortions is found to strongly suppress orbital fluctuations in both YTiO₃ and LaTiO₃ (in the latter less strongly), and to favor the transition to the insulating state.