Optimized micromagnet geometries for Majorana zero modes in low $g$-factor materials

Optimized micromagnet geometries for Majorana zero modes in low $g$ -factor materials

Sara Turcotte, Samuel Boutin, Julien Camirand Lemyre, Ion Garate, and Michel Pioro-Ladrière

Phys. Rev. B 102, 125425 – Published 21 September 2020

Abstract

Solid-state experimental realizations of Majorana bound states are based on materials with strong intrinsic spin-orbit interactions. In this paper, we explore an alternative approach where spin-orbit coupling is induced artificially through a nonuniform magnetic field that originates from an array of micromagnets. Using a recently developed optimization algorithm, we find suitable magnet geometries for the emergence of topological superconductivity in wires without intrinsic spin-orbit coupling. We confirm the robustness of Majorana bound states against disorder and periodic potentials whose amplitudes do not exceed the Zeeman energy. Furthermore, we identify low $g$ -factor materials commonly used in mesoscopic physics experiments as viable candidates for Majorana devices.