English

Minimal charge gap in the ionic Hubbard model

Strongly Correlated Electrons 2009-11-10 v2

Abstract

We study the ionic Hubbard model at temperature T=0 within the mean-field approximation, and show that the charge gap does not close completely at the ionic-band insulator to antiferromagnetic insulator transition, contrary to previous expectations. Furthermore, we find an intermediate phase for on-site repulsions U>UcU>U_c for different lattices, and calculate the phase diagram for the ionic Hubbard model with alternating U, corresponding to a Cu-O lattice.

Keywords

Cite

@article{arxiv.cond-mat/0301376,
  title  = {Minimal charge gap in the ionic Hubbard model},
  author = {K. Pozgajcic and C. Gros},
  journal= {arXiv preprint arXiv:cond-mat/0301376},
  year   = {2009}
}

Comments

5 pages with 7 figures; minor corrections