We argue that in lightly hole doped perovskite-type Mn oxides the holes (Mn4+ sites) are surrounded by nearest neighbor Mn3+ sites in which the occupied 3d orbitals have their lobes directed towards the central hole (Mn4+) site and with spins coupled ferromagnetically to the central spin. This composite object, which can be viewed as a combined orbital-spin-lattice polaron, is accompanied by the breathing type (Mn4+) and Jahn-Teller type (Mn3+) local lattice distortions. We present calculations which indicate that for certain doping levels these orbital polarons may crystallize into a charge and orbitally ordered ferromagnetic insulating state.
@article{arxiv.cond-mat/0011070,
title = {Orbital polarons and ferromagnetic insulators in manganites},
author = {T. Mizokawa and D. I. Khomskii and G. A. Sawatzky},
journal= {arXiv preprint arXiv:cond-mat/0011070},
year = {2009}
}