Origin of robust interaction of spin waves with a single skyrmion in perpendicularly magnetized nanostripes

Abstract

We studied interactions between propagating spin waves (SWs) and a single skyrmion in a perpendicularly magnetized CoFeB nanostripe where the magnetic layer is interfaced with W and MgO. Micromagnetic numerical calculations revealed that robust interactions between the incident SWs and the skyrmion give rise to considerable forward skyrmion motions for specific SW frequencies (e.g., here: fsw = 12 - 19 GHz). Additionally, it was found that there exists a sufficiently low threshold field amplitude, e.g., 0.1 kOe for the fsw = 15 GHz SWs. This frequency-dependent interaction originated from the robust coupling of the SWs with the internal modes of the skyrmion, through the SWs' linear momentum transfer torque acting on the skyrmion. This work provides for all-magnetic control of skyrmion motions without electronic currents, and facilitates further understanding of the interactions between magnons and topological solitons in constricted geometries.