Skyrmion Control of Majorana States in Planar Josephson Junctions

Abstract

Planar Josephson junctions provide a versatile platform, alternative to the nanowire-based geometry, for the generation of the Majorana bound states (MBS), due to the additional phase tunability of the topological superconductivity. The proximity induction of chiral magnetism and superconductivity in a two-dimensional electron gas showed remarkable promises to manipulate topological superconductivity. Here, we propose a new device geometry involving a skyrmion crystal that resolves several issues of the planar Josephson junction and show that the MBS can be created and controlled using the skyrmions. The spin-orbit coupling generated by the skyrmions removes the requirement of a strong intrinsic Rashba spin-orbit coupling, and the phase biasing of the Josephson junction to realize the MBS. The skyrmion radius, being externally tunable by a magnetic field or an anisotropy, offers a useful control knob for the emergence of the MBS.