Direct growth of crystalline SiGe nanowires on superconducting NbTiN thin films

Abstract

Novel heterostructures created by coupling one-dimensional semiconductor nanowires with a superconducting thin film show great potential toward next-generation quantum computing. Here, by growing high-crystalline SiGe nanowires on a NbTiN thin film, the resulting heterostructure exhibits Ohmic characteristics as well as a shift of the superconducting transition temperature (Tc). The structure was characterized at atomic resolution showing a sharp SiGe/NbTiN interface without atomic interdiffusion. Lattice spacing, as calculated from large-area X-ray diffraction experiments, suggests an out-of-plane compressive strain within the NbTiN films upon growth of SiGe nanowires, which explains the downward shift of the superconductivity behavior. The present results provide scientific insights into heterostructure coupling from multi-dimensions showing tunable of superconducting properties that provide benefits for quantum science application.