Majorana bound states with chiral magnetic textures

TL;DR

This paper provides a pedagogical overview of how Majorana bound states can be realized in condensed matter systems with magnetic textures, emphasizing the role of topological superconductivity, magnetic textures, and skyrmions.

Contribution

It introduces a general approach to stabilize Majorana bound states using magnetic textures, including skyrmions, and discusses potential braiding operations.

Findings

Magnetic textures can induce synthetic spin-orbit interactions stabilizing MBS.

Elongated and higher order skyrmions can host MBS.

Braiding operations can be performed with MBS on skyrmions.

Abstract

The aim of this Tutorial is to give a pedagogical introduction into realizations of Majorana fermions, usually termed as Majorana bound states (MBS), in condensed matter systems with magnetic textures. We begin by considering the Kitaev chain model of 'spinless' fermions and show how two 'half' fermions can appear at chain ends due to interactions. By considering this model and its two-dimensional generalization, we emphasize intricate relation between topological superconductivity and possible realizations of MBS. We further discuss how 'spinless' fermions can be realized in more physical systems, e.g., by employing the spin-momentum locking. Next, we demonstrate how magnetic textures can be used to induce synthetic or fictitious spin-orbit interactions, and, thus, stabilize MBS. We describe a general approach that works for arbitrary textures and apply it to skyrmions. We show how MBS can be stabilized by elongated skyrmions, certain higher order skyrmions, and chains of skyrmions. We also discuss how braiding operations can be performed with MBS stabilized on magnetic skyrmions. This Tutorial is aimed at students at graduate level.