Charge Transfer in Iridate-Manganite Superlattices

Charge transfer in superlattices consisting of SrIrO₃ and SrMnO₃ is investigated using density functional theory. Despite the nearly identical work function and nonpolar interfaces between SrIrO₃ and SrMnO₃, 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 nonpolar oxide heterostructures.