Optically controlled ultrafast dynamics of skyrmion in antiferromagnets

Abstract

The optical vortex, an optical beam carrying orbital angular momentum (OAM), has been demonstrated to be promising in manipulating magnetic structure and its dynamics in various systems. In this work, by using numerical and analytical methods, we investigate the optical vortex control of the ultrafast dynamics of skyrmion in antiferromagnets. It is shown that an isolated skyrmion can be generated/erased in an ultrashort time of $\ensuremath{\sim}\mathrm{ps}$ by beam focusing through the Zeeman effect. Subsequently, the OAM can be transferred to the skyrmion and results in its rotation. Different from the case of ferromagnets, the skyrmion rotation direction in antiferromagnets depends on the light frequency, allowing an easy control of the skyrmion rotation via tuning the frequency of light beam. Furthermore, the skyrmion Hall motion, driven by multipolar spin waves that are excited by optical vortex, is revealed in our calculations, demonstrating the dependence of the Hall angle on the OAM quantum number. This work unveils the interesting optical control of the skyrmion dynamics in antiferromagnets, which is a crucial step towards the development of magneto-optic and spintronic applications.