We report first principles characterization of the structural and electronic properties of (SrTiO3)5/(SrRuO3)1 superlattices. We show that the system exhibits a spin-polarized two-dimensional electron gas, extremely confined to the 4d orbitals of Ru in the SrRuO3 layer. Every interface in the superlattice behaves as a minority-spin half-metal ferromagnet, with a magnetic moment of μ = 2.0 μB/SrRuO3 unit. The shape of the electronic density of states, half metallicity and magnetism are explained in terms of a simplified tight-binding model, considering only the t2g orbitals plus (i) the bi-dimensionality of the system, and (ii) strong electron correlations.
@article{arxiv.1201.3036,
title = {Highly-confined spin-polarized two-dimensional electron gas in SrTiO$_{3}$/SrRuO$_{3}$ superlattices},
author = {Marcos Verissimo-Alves and Pablo García-Fernández and Daniel I. Bilc and Philippe Ghosez and Javier Junquera},
journal= {arXiv preprint arXiv:1201.3036},
year = {2015}
}