Magnon driven skyrmion dynamics in antiferromagnets: The effect of magnon polarization

TL;DR

This paper explores how magnon polarization influences skyrmion motion in antiferromagnets, revealing complex scattering behaviors and conditions for controlling skyrmion Hall effects, which are crucial for spintronic device development.

Contribution

It provides a detailed theoretical analysis of magnon-driven skyrmion dynamics in antiferromagnets, emphasizing the role of magnon polarization and uncovering new scattering phenomena.

Findings

Circularly polarized magnons induce inevitable skyrmion Hall motion.

Linearly polarized magnons have a complex dependence on skyrmion motion.

Mirror symmetry breaking leads to skyrmion Hall motion, which can be suppressed under specific conditions.

Abstract

The controllable magnetic skyrmion motion represents a highly concerned 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 ultra-low energy consumption. In this work, we investigate extensively the dynamics of skyrmion motion driven by magnon in an antiferromagnet using the collective coordinate theory, focusing on the effect of magnon polarization. It is revealed that the skyrmion Hall motion driven by circularly polarized magnon becomes inevitable generally, consistent with earlier report. Furthermore, the elastic scattering theory and numerical results unveil the strong inter-dependence between the linearly polarized magnon and skyrmion motion, suggesting the complicated dependence of the skyrmion motion on the polarization nature of driving magnon. 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 skyrmion is generated owing to the broken mirror symmetry, which in turn drives a skyrmion Hall motion. The Hall motion can be completely suppressed only in some specific condition where the mirror symmetry is preserved. The present work unveils non-trivial skyrmion-magnon scattering behavior in antiferromagnets, advancing the antiferromagnetic spintronics and benefiting to high-performance devices.