Mechanism for Orbital Ordering in KCuF3

作者:Pavarini E*; Koch E; Lichtenstein A I
来源:Physical Review Letters, 2008, 101(26): 266405.
DOI:10.1103/PhysRevLett.101.266405

摘要

The Mott insulating perovskite KCuF3 is considered the archetype of an orbitally ordered system. By using the local-density approximation+dynamical mean-field theory method, we investigate the mechanism for orbital ordering in this material. We show that the purely electronic Kugel-Khomskii superexchange mechanism alone leads to a remarkably large transition temperature of T-KK similar to 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.

  • 出版日期2008-12-31