The origin of ferromagnetic insulating state of La7/8Sr1/8MnO3 is investigated. Based on the tight-binding model, it is shown that this state can be attributed to the Peierls instability arisen from the interplay of spin and orbital ordering. The importance of the hole-orbiton-phonon intercoupling in doped manganites is revealed. This picture explains well the recent experimental finding of the reentrance of ferromagnetic metal state at low temperature [Phys. Rev. Lett. 96, 097201 (2006)].
@article{arxiv.0811.2019,
title = {Peierls Instability Induced Ferromagnetic Insulator at Orbital Order Transition},
author = {J. H Wei and D. Hou and X. R. Wang},
journal= {arXiv preprint arXiv:0811.2019},
year = {2010}
}