Spin transfer torque and field driven 360° domain wall to bimeron conversion

Abstract

In this work, using micromagnetic simulations we study the mechanism involved in the conversion of a 360° domain wall into stable pairs of bimeron (Q = +1) and antibimeron (Q = -1) in a ferromagnetic background when it is subjected to Zhang Li type of spin transfer torque. We show that the time scales associated with the conversion process can be significantly reduced by applying out of plane bias field. In particular, choosing a constant inclination angle and increasing the intensity of bias field aids in reducing the energy barrier required to stabilize the spin textures. Similarly, for a constant bias field intensity, varying the inclination angle between 0° to 40° reveals that the time required to stabilize the first bimeron is reduced by ∼ 3 ns. Further, tailoring the strength of in-plane current density as well as effective uniaxial anisotropy leads to faster conversion of domain wall to bimerons.