Spin-wave resonance reflection and spin-wave induced domain wall displacement

Abstract

Spin-wave propagation and spin-wave induced domain wall motion in nanostrips with a Néel wall are studied by micromagnetic simulations. It is found that the reflection of spin waves by the wall can be resonantly excited due to the interaction between spin waves and domain-wall normal modes. With the decrease of the saturation magnetization Ms (and the consequent increase of the wall width), the reflection is diminished and complete transmission can occur. The domain wall motion induced by spin waves is closely related to the spin-wave reflectivity of the wall, and may exhibit different types of behavior. The reflected spin waves (or magnons) give rise to a magnonic linear momentum-transfer torque, which drives the wall to move along the spin wave propagation direction. The maximal velocity of the domain wall motion corresponds to the resonance reflection of the spin waves. The transmitted spin waves (or magnons) lead to a magnonic spin-transfer torque, which drags the wall to move backwardly. The complicated domain wall motion can be described qualitatively by a one-dimensional model incorporating both the magnonic linear momentum-transfer torque and the magnonic spin-transfer torque. The results obtained here may find use in designing magnonic nanodevices.