Topological superconductivity in hybrid devices

Topological superconductivity can emerge from the combination of conventional superconductivity in a metal and strong spin–orbit coupling in a semiconductor when they are made into a hybrid device. The most exciting manifestation of topological superconductivity is the Majorana zero modes that are predicted to exist at the ends of the proximatized nanowires. In this Perspective, we review the evidence for the existence of Majorana zero modes that has accumulated in numerous experiments and the remaining uncertainties, and discuss what additional evidence is desirable. One very important factor for future development is the quality of the interface between the superconductor and semiconductor; we sketch out where further progress in the materials science of these interfaces can take us. We then discuss the path towards applying these modes in topologically protected quantum computing and observing more exotic kinds of superconductivity based on the same materials platform, and how to make connections to high-energy physics. Hybrid devices of superconductors and semiconductor nanowires may be topological and host majorana. This Perspective summarizes the current situation of the field, and highlights the developments in materials science required to make progress.