Full-shell hybrid nanowires, a promising semiconducting nanowire design in the search for Majorana modes

Hybrid superconductor-semiconductor nanowires are being intensively studied in an effort to detect and manipulate Majorana bound states. Traditionally, a superconductor is deposited or grown epitaxially over some of the facets of the semiconducting wire and a Zeeman field is applied to drive the system into the topological regime. One of the main drawbacks of this platform is the need to subject the wire to strong magnetic fields that degrade the superconducting state of the parent superconductor. In the last couple of years, new nanowire configurations are being explored that could present some advantages with respect to previous designs. In this talk, I will discuss theoretical and experimental progress on one the most promising proposals: the so-called full-shell nanowires, where the semiconducting nanowire is fully coated with a superconducting shell. These wires could develop Majorana modes in the presence of small external magnetic fields not driven by the Zeeman effect, but by the winding of the superconducting phase around the semiconducting core.