Charge transfer across transition metal oxide interfaces: emergent conductance and new electronic structure

TL;DR

This study uses advanced computational methods to explore how internal charge transfer in layered transition metal oxides affects their electronic properties, revealing new ways to engineer their electronic structure.

Contribution

It demonstrates that combining charge transfer and quantum confinement in heterostructures can effectively tailor the electronic and correlation effects in transition metal oxides.

Findings

Moderate charge transfer from VO2 to MnO2 layers due to electronegativity differences

Charge transfer leads to hole doping in VO2 and electron doping in MnO2 layers

Insights into the role of apical oxygen in heterostructure electronic properties

Abstract

We perform density functional theory plus dynamical mean field theory calculations to investi- gate internal charge transfer in an artificial superlattice composed of alternating layers of vanadate and manganite perovskite and Ruddlesden-Popper structure materials. We show that the elec- tronegativity difference between vanadium and manganese causes moderate charge transfer from VO2 to MnO2 layers in both perovskite and Ruddlesden-Popper based superlattices, leading to hole doping of the VO2 layer and electron doping of the MnO2 layer. Comparison of the perovskite and Ruddlesden-Popper based heterostructures provides insights into the role of the apical oxy- gen. Our first principles simulations demonstrate that the combination of internal charge transfer and quantum confinement provided by heterostructuring is a powerful approach to engineering electronic structure and tailoring correlation effects in transition metal oxides.