Metal-insulator transitions: Influence of lattice structure, Jahn-Teller effect, and Hund's rule coupling
Strongly Correlated Electrons
2009-10-31 v1
Abstract
We study the influence of the lattice structure, the Jahn-Teller effect and the Hund's rule coupling on a metal-insulator transition in AnC60 (A= K, Rb). The difference in lattice structure favors A3C60 (fcc) being a metal and A4C60 (bct) being an insulator, and the coupling to Hg Jahn-Teller phonons favors A4C60 being nonmagnetic. The coupling to Hg (Ag) phonons decreases (increases) the value Uc of the Coulomb integral at which the metal-insulator transition occurs. There is an important partial cancellation between the Jahn-Teller effect and the Hund's rule coupling.
Keywords
Cite
@article{arxiv.cond-mat/9910319,
title = {Metal-insulator transitions: Influence of lattice structure, Jahn-Teller effect, and Hund's rule coupling},
author = {J. E. Han and E. Koch and O. Gunnarsson},
journal= {arXiv preprint arXiv:cond-mat/9910319},
year = {2009}
}
Comments
4 pages, RevTeX, 3 eps figure, additional material available at http://www.mpi-stuttgart.mpg.de/docs/ANDERSEN/fullerene/