Spectral-weight function of the ionic Hubbard model
Strongly Correlated Electrons
2007-05-23 v1
Abstract
The one-electron spectral-weight function of the half-filled ionic Hubbard model is calculated by means of Quantum Monte Carlo. A metallic regimen occurs between two values of the coupling constant (Hubbard U) U1 < U2 . The system is a band insulator below U1, and an increasingly antiferromagnetic (AF) insulator above U2 evolving into a Mott insulator as U tends to infinity . The intermediate regimen which is both AF and dimerized, is caused by a two-peak structure at k = 0,5 pi (the Fermi surface). As U increases both peaks approach each other, overlap, and separate again, the system becoming metallic in the overlap region.
Cite
@article{arxiv.cond-mat/0210462,
title = {Spectral-weight function of the ionic Hubbard model},
author = {M. C. Refolio and J. M. Lopez Sancho and J. Rubio},
journal= {arXiv preprint arXiv:cond-mat/0210462},
year = {2007}
}