The influence of the Majorana non-locality on the supercurrent

Abstract

We study the equilibrium Josephson current between an s-wave superconductor and a topological superconducting nanowire with Majorana bound states (MBS) at its ends. Within a low-energy model we show analytically that the non-locality of the MBS allows for a finite supercurrent to flow that otherwise would vanish. In particular, we find the critical current to be a function of the difference in the spin canting angles of the Majorana wave functions at the location of the tunnel contact. We complement our analytical calculations by numerically solving the full tight binding model and show how to extract the main features of the low-energy model from the critical current using available experimental techniques.