Static Structures and Dynamics of Frustrated Topological Spin Textures

Abstract

The magnetic spin textures with non-trivial topology has been an important topic in the fields of magnetism and spintronics for the last few years [1]. For example, the magnetic skyrmion is a promising topological spin texture, which exists in perpendicularly magnetized systems and can be used as a spintronic information carrier. On the other hand, magnetic bimeron is a topological counterpart of skyrmions in in-plane magnets, which can also be used to carry information. In this talk, we will show the static properties of skyrmions and bimerons with different topological structures in a frustrated ferromagnetic monolayer [2], where the topological spin textures are characterized by the vorticity Qv and helicity η. We will also talk about the dynamics of frustrated skyrmions and bimerons driven by the spin-orbit torques, which depend on the strength of the damping-like and field-like torques. We find that these particle-like topological spin textures with Qv = ±1 can be driven into linear or elliptical motion, which depends on the direction of spin polarization. We numerically reveal the damping dependence of the skyrmion/bimeron Hall angle driven by the damping-like torque. Besides, we will show that the isolated bimeron with Qv = ±1 can be driven into self-rotation by the damping-like torque at certain conditions. The rotation frequency is proportional to the driving current density. In addition, we will computationally demonstrate the possibility of creating a bimeron state with a higher or lower topological charge by the current-driven collision and merging of bimeron states with different Qv. Finally, we will give an outlook on other possible topological spin textures in frustrated magnetic systems, such as the skyrmionium and bimeronium. We believe the results presented in this talk could be useful for understanding the topological spin textures physics in frustrated magnetic systems. **