Damped orbital excitations in the titanates
Abstract
A possible mechanism for the removal of the orbital degeneracy in RTiO3 (where R=La, Y, ...) is considered. The calculation is based on the Kugel-Khomskii Hamiltonian for electrons residing in the t2g orbitals of the Ti ions, and uses a self-consistent pe rturbation expansion in the interaction between the orbital and the spin degrees of freedom. The latter are assumed to be ordered in a Neel state, brought about by delicate interactions that are not included in the Kugel-Khomskii Hamiltonian. Within our model calculations, each of the t2g bands is found to acquire a finite, temperature-dependent dispersion, that lifts the orbital degeneracy. The orbital excitations are found to be heavily damped over a rather wide band. Consequently, they do not participate as a separate branch of excitations in the low-temperature thermodynamics.e
Keywords
Cite
@article{arxiv.cond-mat/0302182,
title = {Damped orbital excitations in the titanates},
author = {K. Kikoin and O. Entin-Wohlman and V. Fleurov and A. Aharony},
journal= {arXiv preprint arXiv:cond-mat/0302182},
year = {2009}
}
Comments
6 pages, 3 figures