At interfaces between polar and nonpolar perovskite oxides, an unusual electron-doping has been previously observed, due to electronic reconstructions. We report on remote hole-doping at an interface composed of only polar layers, revealed by high-resolution hard x-ray core-level photoemission spectroscopy. In LaAlO3/LaVO3/LaAlO3 trilayers, the vanadium valence systematically evolves from the bulk value of V3+ to higher oxidation states with decreasing LaAlO3 cap layer thickness. These results provide a synthetic approach to hole-doping transition metal oxide heterointerfaces without invoking a polar discontinuity.
@article{arxiv.0806.2191,
title = {Remote hole-doping of Mott insulators on the nanometer scale},
author = {M. Takizawa and Y. Hotta and T. Susaki and Y. Ishida and H. Wadati and Y. Takata and K. Horiba and M. Matsunami and S. Shin and M. Yabashi and K. Tamasaku and N. Nishino and T. Ishikawa and A. Fujimori and H. Y. Hwang},
journal= {arXiv preprint arXiv:0806.2191},
year = {2009}
}