We investigate ferrimagnetic domain-wall dynamics induced by circularly polarized spin waves theoretically and numerically. We find that the direction of domain-wall motion depends on both the circular polarization of spin waves and the sign of net spin density of the ferrimagnet. Below the angular momentum compensation point, left- circularly (right-circularly) polarized spin waves push a domain wall towards (away from) the spin-wave source. Above the angular momentum compensation point, on the other hand, the direction of domain-wall motion is reversed. This bidirectional motion originates from the fact that the sign of spin-wave-induced magnonic torque depends on the circular polarization and the subsequent response of the domain wall to the magnonic torque is governed by the net spin density. Our finding provides a way to utilize a spin wave as a versatile driving force for bidirectional domain-wall motion.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (Grants No. 2015M3D1A1070465 and No. 2017R1A2B2006119) and the Korea Institute of Science and Technology (KIST) Institutional Program (Project No. 2V05750). S.K.K. was supported by a startup fund at the University of Missouri. J.X. was supported by the National Natural Science Foundation of China (Grant No. 11722430).
© 2019 American Physical Society.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics