Epitaxial Antiperovskite/Perovskite Heterostructures for Materials Design*

Engineered heterostructures formed by complex oxide materials are a rich source of emergent phenomena and technological applications. In the quest for new functionality, a vastly unexplored avenue is interfacing oxide perovskites with materials having dissimilar crystallochemical properties. Here, a unique class of heterointerfaces based on nitride antiperovskite and oxide perovskite materials is engineered as a new direction for materials design. Atomically sharp interfaces between nitride antiperovskite Mn 3 GaN with noncollinear spin structure and oxide perovskites (La _0.3 Sr _0.7 )(Al _0.65 Ta _0.35 )O ₃ (LSAT) and SrTiO ₃ are fabricated, and atomic resolution imaging / spectroscopic techniques and first-principle calculations, are used to determine the atomic-scale structure, composition, and bonding at the interface. The epitaxial antiperovskite / perovskite heterointerface is mediated by a coherent interfacial monolayer that interpolates between the two anti-structures. These results represent a major step for the development of functional antiperovskite/perovskite heterostructures, combining their unique characteristics such as topological properties for ultra low power applications. We also discuss a heterostructure application exploiting charge to spin conversion arising from the noncollinear spin structure.