A theory of heterostructures comprised of LaTiO3 (a Mott insulator) and SrTiO3 (a band insulator) is presented. The band structure of the Ti d% -electrons is treated with a nearest neighbor tight-binding approximation; the electric fields arising from the La3+/Sr2+ charge difference and the carriers are treated within a Hartree approximation; and the on-site interactions are treated by unrestricted Hartree-Fock. The phase diagram as a function of interaction strength and layer number is determined and predictions are made for optical conductivity experiments. A note worthy finding is that the edges of the heterostructure are generally metallic.
@article{arxiv.cond-mat/0404275,
title = {Theory of Mott insulator/band insulator heterostructure},
author = {Satoshi Okamoto and Andrew J. Millis},
journal= {arXiv preprint arXiv:cond-mat/0404275},
year = {2009}
}