Magnon-Driven Skyrmion Dynamics In Antiferromagnets: Effect Of Magnon Polarization

Controllable magnetic skyrmion motion represents a highly relevant issue in preparing advanced skyrmion-based spintronic devices. Specifically, magnon-driven skyrmion motion can be easily accessible in both metallic and insulating magnets and thus is highly preferred over electric current control, further for the ultralow energy consumption. In this paper, we investigate extensively the dynamics of skyrmion motion driven by magnons in an antiferromagnet using the collective coordinate theory, focusing on the effect of magnon polarization. It is theoretically revealed that skyrmion Hall motion driven by circularly polarized magnons becomes inevitable generally, benefiting a comprehensive understanding of antiferromagnetic (AFM) skyrmion dynamics. More importantly, the elastic scattering theory and numerical results unveil the strong interdependence between linearly polarized magnons and skyrmion motion, suggesting the complicated dependence of skyrmion motion on the polarization nature of driving magnons. On the reversal, the scattering from the moving skyrmion may lead to decomposition of the linearly polarized magnon into two elliptically polarized magnon bands. Consequently, a net transverse force acting on the skyrmion is generated owing to the broken mirror symmetry, which in turn drives skyrmion Hall motion. Hall motion can be completely suppressed only in a specific condition where the mirror symmetry is preserved. This paper unveils nontrivial skyrmion-magnon scattering behavior in antiferromagnets, advancing AFM spintronics and benefiting high-performance devices.