Metallicity at the Unit Cell in Rutile (Ru,Ir)O₂ Oxides

Rutile 4d/5d-transition metal oxides, such as RuO₂ and IrO₂, exhibit intriguing crystal structures characterized by both edge- and corner-sharing octahedra. This inherent crystal anisotropy, when coupled with strain-engineering, offers a pathway to introduce and fine-tune anisotropic electronic and optical properties. In this talk, I will address the challenges associated with achieving atomic-level control in the synthesis of RuO₂ and IrO₂ and present our group's efforts to overcome these obstacles using hybrid molecular beam epitaxy (hMBE). By carefully optimizing the growth parameters, we demonstrate metallicity in these oxides down to the unit cell scale. Through a combination of advanced X-ray scattering, X-ray absorption spectroscopy, temperature-dependent transport measurements, and density functional theory (DFT) calculations, I will discuss the anisotropic crystal structures in detail and their impact on the resulting electronic, magnetic and optical properties.