Remote hole-doping of Mott insulators on the nanometer scale

TL;DR

This study demonstrates remote hole-doping in transition metal oxide heterostructures through interface engineering, revealing a new method to control electronic properties without polar discontinuity.

Contribution

It introduces a novel approach for hole-doping transition metal oxides at interfaces using only polar layers, bypassing the need for polar discontinuity.

Findings

Vanadium valence shifts from V3+ to higher oxidation states with thinner LaAlO3 layers.

Hole-doping achieved without polar discontinuity.

High-resolution spectroscopy confirms electronic reconstruction.

Abstract

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.