Anisotropic electronic structure of epitaxial (110) RuO₂ films

Anisotropy of correlated electrons provides both fundamental understanding and inspiration for future device applications. The (110)-oriented RuO₂ rutile film on rutile TiO₂ (110) substrates provides highly anisotropic epitaxial strain along two in-plane directions along [001] and [1 0]. These epitaxial strains can further be tailored via film thickness enabling potentially a systematic control over anisotropic electronic behavior in RuO₂ films. In this talk, we will present a systematic growth of RuO₂ films on TiO₂ (110) substrates using hybrid molecular beam epitaxy. Combining X-ray and electron diffractions, X-ray absorption spectroscopy, temperature-dependent magnetotransport, and optical spectroscopy, we will discuss the relationship between crystal structure, orbital hybridization, and the electrical transport in RuO₂ films.