Rutile IrO2/TiO2 superlattices: A hyperconnected analog to the Ruddelsden-Popper structure

Emergent properties in transition metal oxide superlattices are traditionally tuned as functions of stoichiometry, reduced dimensionality, and epitaxial strain. Here the authors introduce a new tuning parameter, the connectivity of the $M$O${}_{6}$ octahedra ($M=$ transition metal), as a means to manipulate the electronic structure, symmetry, and competing ground states of oxide superlattices. They demonstrate this by the epitaxial growth of alternating layers of the high spin-orbit metal IrO${}_{2}$ and the band insulator TiO${}_{2}$, both of which have the rutile structure.