Growth and Transport in InAs Nanowires with ZnTe Shell for Definitive Majorana Zero Modes in Optimized Hybrid Nanowires

We propose a Majorana fermion platform based on InAs nanowires capped by ZnTe and proximitized with a superconductor Sn. We predict that coating InAs nanowires with a ZnTe shell of varying thickness can modify the nanowire band structure to suppress subgap states. Additionally, the ZnTe shell is expected to enhance carrier mobility by repelling charge carriers from surface. We achieved epitaxy growth between InAs-core and ZnTe-shell, homogeneity along the nanowire, and thickness control of ZnTe shell with Molecular-beam epitaxy. We fabricated and characterized 84 InAs nanowires with ZnTe shell thicknesses ranging from 0 to 15 nm. Field-effect measurements were performed, from which we extracted hysteresis, pinch-off voltage, current saturation, charge mobility, and subthreshold slope. Contrary to our initial prediction, we find that the ZnTe shell reduces the carrier mobility in InAs nanowires. We will proceed to study transport between nanowire and superconductor.