Magnetic Droplet Solitons from Unconventional Out-of-Plane Spin Orbit Torques

Mirror symmetry breaking in non-colinear antiferromagnets due to magnetic order can generate unconventional out-of-plane (OOP) spin orbit torques (SOTs). Unlike conventional in-plane (IP) SOTs, these torques can be used to manipulate magnetization in materials with perpendicular magnetic anisotropy (PMA). Towards this end, we investigated with micromagnetic simulations if these unconventional OOP SOTs can generate droplet solitons in rectangular geometries. The IP and OOP angles of the spin polarization play an important role for the droplet nucleation, while the applied magnetic field and current affect the precession frequency. Depending on the duration of the current pulse the nucleation of multiple droplets is possible, which interact with each other. Finally we discuss strategies for experimental implementations for spin-orbit torque driven droplets.