Electronic reconstruction at SrMnO3-LaMnO3 superlattice interfaces

TL;DR

This study uses resonant soft x-ray scattering to reveal electronic reconstruction at SrMnO3-LaMnO3 interfaces, showing a peak at the Fermi level linked to metallicity and magnetism, demonstrating a method to probe interface electronic states.

Contribution

It introduces a resonant soft x-ray scattering technique to directly observe electronic states at oxide interfaces, providing insights into their metallic and magnetic properties.

Findings

Peak at Fermi level correlates with conductivity.

Interface electronic states drive metallic behavior.

Method demonstrates probing of heterostructure interfaces.

Abstract

We use resonant soft x-ray scattering to study electronic reconstruction at the interface between the Mott insulator LaMnO3 and the "band" insulator SrMnO3. Superlattices of these two insulators were shown previously to have both ferromagnetism and metallic tendencies [Koida et al., Phys. Rev. B 66, 144418 (2002)]. By studying a judiciously chosen superlattice reflection we show that the interface density of states exhibits a pronounced peak at the Fermi level, similar to that predicted by Okamoto et al. [Phys. Rev. B 70, 241104(R) (2004)]. The intensity of this peak correlates with the conductivity and magnetization, suggesting it is the driver of metallic behavior. Our study demonstrates a general strategy for using RSXS to probe the electronic properties of heterostructure interfaces.