Spin waves and transverse domain walls driven by spin waves: Role of damping**Project supported by the National Natural Science Foundation of China (Grant Nos. 61774001 and 51972103), the Natural Science Foundation of Hebei Province of China (Grant No. F2019202141), and the Fund of the State Key Laboratory of Quantum Optics and Quantum Optics Devices, Shanxi University, China (Grant No. KF201906).

Abstract

Based on the uniform, helical and spiral domain-wall magnetic configurations, the excited spin waves are studied with emphasis on the role of damping. We find that the damping closes the gap of dispersion, and greatly influences the dispersion in the long-wave region for the spin waves of spiral wall and helical structure. For the uniform configuration, the Dzyaloshinskii–Moriya interaction determines the modification of dispersion by the damping. Furthermore, we investigate the interaction between spin waves and a moving spiral domain wall. In the presence of damping, the amplitude of spin wave can increase after running across the wall for small wave numbers. Driving by the spin waves, the wall propagates towards the spin-wave source with an increasing velocity. Unlike the case without damping, the relation between the wall velocity and the spin-wave frequency depends on the position of wall.