Ab initio Study and Search of Chalcogenide-oxide Interfaces

The discovery of interface enhanced superconductivity has sparked interest in studying interfacial properties of quantum materials. Experimental and theoretical efforts highlight the relevance of spin fluctuation, orbital order and electron-phonon coupling to the onset enhanced superconducting behavior. However, the exact mechanism responsible for increased Tc is still not well-understood. Inspired by recent observations of interface enhanced superconductivity in FeSe/SrTiO₃ system and ultrathin film CuS₂, we use ab initio theoretical tools to investigate interfacial properties. We investigate interfacial effects on electronic structure, electron-electron and electron-phonon interactions, as well as study the effect of interlayer coupling in chalcogenide-oxide structures. Additionally, we aim to use our methods to identify superconducting interfaces in other chalcogenide material and substrate combinations. These theoretical investigations provide avenues to design and search for superconducting chalcogenide-oxide interfaces.