A Universal Way to Engineer the Electronic Properties of Hybrid Devices.

The hybrid devices of superconductor and semiconductor nanowire (NW) with strong spin-orbit interaction (SOI) can be driven to topological regime and host Majorana zero modes (MZMs), which are the building blocks of a topological computer. Here we fabricate hybrid devices with thick/thin Al/Pb film. By well controlling the etching time, we can modify the band bending strength of interface and control the electronic properties. This is demonstrated by that the Al-InSb devices with different etching time shows quantized plateaus with varying number of modes. Moreover, high transmission of channels got by fitting the multiple Andreev reflection also proves the high quality of interface. In the thin Pb-NW devices, we observed gate tunable induced hard superconducting gap from 0 to ~1.4meV, with a suppression of conductance by three orders of magnitude. The effective g-factors, calculated through the evolution of states as a function of magnetic field, are remarkably large, e.g. several tens or even more than one hundred. This indicates the orbital effect and the strong SOI of Pb film. With the combination of pronounced enhancement of induced superconducting gap and g-factor, Pb-NW provides a better platform than Al-NW for searching for MZMs, as well as constructing topological qubit.