Effects of the electrostatic environment on the Majorana nanowire devices

Abstract

One of the promising platforms for creating Majorana bound states is a hybrid nanostructureconsisting of a semiconducting nanowire covered by a superconductor. We analyze the previouslydisregarded role of electrostatic interaction in these devices. Our main result is that Coulombinteraction causes the chemical potential to respond to an applied magneticfield, while spin–orbitinteraction and screening by the superconducting lead suppress this response. Consequently, theelectrostatic environment influences two properties of Majorana devices: the shape of the topologicalphase boundary and the oscillations of the Majorana splitting energy. We demonstrate that bothproperties show a non-universal behavior, and depend on the details of the electrostatic environment.We show that when the wire only contains a single electron mode, the experimentally accessibleinverse self-capacitance of this mode fully captures the interplay between electrostatics and Zeemanfield. This offers a way to compare theoretical predictions with experiments