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

TL;DR

This study investigates how spin waves interact with a single skyrmion in a nanostripe, revealing frequency-dependent coupling that enables magnetic control of skyrmion motion without electronic currents.

Contribution

It demonstrates the robust, frequency-dependent interaction between propagating spin waves and skyrmions, enabling all-magnetic control of skyrmion dynamics in nanostripes.

Findings

Significant forward skyrmion motion at specific spin wave frequencies (12-19 GHz).

Existence of a low threshold field amplitude (~0.1 kOe) for effective skyrmion manipulation.

Interaction driven by coupling of spin waves with skyrmion internal modes via momentum transfer.

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.