Ab initio calculations are used to predict that a superlattice composed of layers of LaTiO3 and LaNiO3 alternating along the [001] direction is a S=1 Mott insulator with large magnetic moments on the Ni sites, negligible moments on the Ti sites and a charge transfer gap set by the energy difference between Ni d and Ti d states, distinct from conventional Mott insulators. Correlation effects are enhanced on the Ni sites via filling the oxygen p states and reducing the Ni-O-Ni bond angle. Small hole (electron) doping of the superlattice leads to a two-dimensional single-band situation with holes (electrons) residing on Ni dx2-y2 (Ti dxy) orbital and coupled to antiferromagnetically correlated spins in the NiO2 layer.
@article{arxiv.1304.7815,
title = {Engineering Correlation Effects via Artificially Designed Oxide Superlattices},
author = {Hanghui Chen and Chris A. Marianetti and Andrew J. Millis},
journal= {arXiv preprint arXiv:1304.7815},
year = {2015}
}