  We report the formation of a non-magnetic band insulator at the isopolar
interface between the antiferromagnetic Mott-Hubbard insulator LaTiO3 and the
antiferromagnetic charge transfer insulator LaFeO3. By density functional
theory calculations, we find that the formation of this interface state is
driven by the combination of O band alignment and crystal field splitting
energy of the t2g and eg bands. As a result of these two driving forces, the Fe
3d bands rearrange and electrons are transferred from Ti to Fe. This picture is
supported by x-ray photoelectron spectroscopy, which confirms the rearrangement
of the Fe 3d bands and reveals an unprecedented charge transfer up to 1.2+/-0.2
e-/interface unit cell in our LaTiO3/LaFeO3 heterostructures.

Strongly Correlated Electrons;Materials Science