Charge transfer in iridate-manganite superlattices

TL;DR

This study combines theoretical modeling and experimental verification to understand charge transfer mechanisms in SrIrO3/SrMnO3 superlattices, revealing strain-dependent behavior and offering new ways to control electronic states in oxide heterostructures.

Contribution

The paper presents a microscopic model explaining charge transfer in iridate-manganite superlattices and demonstrates its strain dependence through experimental validation.

Findings

Large charge transfer occurs despite similar work functions.

Charge transfer exhibits a strong dependence on strain.

Experimental results confirm the theoretical predictions.

Abstract

Charge transfer in superlattices consisting of SrIrO$_3$ and SrMnO$_3$ is investigated using density functional theory. Despite the nearly identical work function and non-polar interfaces between SrIrO$_3$ and SrMnO$_3$, rather large charge transfer was experimentally reported at the interface between them. Here, we report a microscopic model that captures the mechanism behind this phenomenon, providing a qualitative understanding of the experimental observation. This leads to unique strain dependence of such charge transfer in iridate-manganite superlattices. The predicted behavior is consistently verified by experiment with soft x-ray and optical spectroscopy. Our work thus demonstrates a new route to control electronic states in non-polar oxide heterostructures.