Magnetic 2π Domain Walls for Tunable Majorana Devices

Topological quantum computing aims to solve scaling and stability issues with current quantum computing platforms. Majorana bound states (MBSes) are a necessary ingredient for most proposals for topological quantum computing. Magnet-superconductor hybrids (MSHes) provide a promising platform for finding MBSes. We analyse the topology of MSHes with a magnetic 2π domain wall texture on the magnetic side and s-wave pairing and Rashba spin-orbit coupling (SOC) in the superconductor. The two layers are coupled with an antiferromagnetic exchange coupling. With this, we extend previous proposals concerning elongated skyrmions. We show that magnetic 2π domain walls are suitable for hosting MBSes and are advantageous compared to elongated skyrmions both for their attainability and mobility and for sidestepping issues with out-of-plane fields due to Pauli limiting. For various parameters of the system, we examine their influence on the topological phase space. Finally, we analyse the dynamics of the system under movement of the domain wall and show that MBSes can be moved in this way. This makes MSHes with magnetic 2π domain walls a suitable candidate for approachable and tunable Majorana devices.