On the mechanism for orbital-ordering in KCuF3

Abstract

The Mott insulating perovskite KCuF3 is considered the archetype of an orbitally-ordered system. By using the LDA+dynamical mean-field theory (DMFT) method, we investigate the mechanism for orbital-ordering (OO) in this material. We show that the purely electronic Kugel-Khomskii super-exchange mechanism (KK) alone leads to a remarkably large transition temperature of T_KK about 350 K. However, orbital-order is experimentally believed to persist to at least 800 K. Thus Jahn-Teller distortions are essential for stabilizing orbital-order at such high temperatures.

4 pages, 5 figures

References in corpus (3)

• Orbital fluctuations in the different phases of LaVO3 and YVO3
• Structural relaxation due to electronic correlations in the paramagnetic insulator KCuF3
• Effect of Crystal-Field Splitting and Inter-Band Hybridization on the Metal-Insulator Transitions of Strongly Correlated Systems

Cited by in corpus (5)

• Importance of exchange-anisotropy and superexchange for the spin-state transitions in LnCoO3 (Ln=La,Y,RE) cobaltates
• Structural and metal-insulator transitions in rhenium based double perovskites via orbital ordering
• Orbiton-magnon interplay in the spin-orbital polarons of KCuF3 and LaMnO3
• LaVO${}_3$: a true Kugel-Khomskii system
• Spin-dimer ground state driven by consecutive charge and orbital ordering transitions in the anionic mixed-valence compound Rb${}_4$O${}_6$