One-dimensional confinement and enhanced Jahn-Teller instability in LaVO3.
Ordering and quantum fluctuations of orbital degrees of freedom are studied theoretically for LaVO3 in the spin-C-type antiferromagnetic state. The effective Hamiltonian for the orbital pseudospin shows strong one-dimensional anisotropy due to the negative interference among various exchange processes. This significantly enhances the instability toward lattice distortions for the realistic estimate of the Jahn-Teller coupling by first-principle LDA+U calculations, instead of favoring the orbital singlet formation. This explains well the experimental results on the anisotropic optical spectra as well as the proximity of the two transition temperatures for spin and orbital orderings.
Motome
Yukitoshi
Y
Tokura Spin SuperStructure Project (SSS), ERATO, Japan Science and Technology Corporation, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 4, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562, Japan.
Seo
Hitoshi
H
Fang
Zhong
Z
Nagaosa
Naoto
N