We report spectroscopic ellipsometry measurements of the anisotropy of the interband transitions parallel and perpendicular to the planes of (LaTiO3)n(LaAlO3)5 multilayers with n = 1-3. These provide direct information about the electronic structure of the two-dimensional (2D) 3d^1 state of the Ti ions. In combination with LDA+U calculations, we suggest that 2D confinement in the TiO2 slabs lifts the degeneracy of the t_{2g} states leaving only the planar d_xy orbitals occupied. We outline that these multilayers can serve as a model system for the study of the t_{2g} 2D Hubbard model.
@article{arxiv.0912.3863,
title = {Two-Dimensional Confinement of 3d1 Electrons in LaTiO3/LaAlO3 Multilayers},
author = {S. S. A. Seo and M. J. Han and G. W. J. Hassink and W. S. Choi and S. J. Moon and J. S. Kim and T. Susaki and Y. S. Lee and J. Yu and C. Bernhard and H. Y. Hwang and G. Rijnders and D. H. A. Blank and B. Keimer and T. W. Noh},
journal= {arXiv preprint arXiv:0912.3863},
year = {2013}
}
Comments
7 pages, 4 figures. Accepted for publication in Phys. Rev. Lett