Domain wall dynamics driven by sinusoidal polarized magnetic field in ferrimagnets

Abstract

Ferrimagnetic domain walls are attracting more and more attentions due to their interesting physics and potential applications in future spintronic devices, particularly attributes to the non-zero net magnetization and ultrafast dynamic properties. Exploring effective methods for driving domain walls with low energy consumption and high efficiency does provide important information for experimental design and device development. In this work, we study theoretically and numerically the dynamics of ferrimagnetic domain wall driven by the sinusoidal microwave magnetic field using the collective coordinate theory and Landau-Lifshitz-Gilbert simulations of atomistic spin model. It is revealed that the microwave field can drive the propagation of the domain wall along nanowires when the frequency falls into appropriate regions, which allows one to modulate the domain wall dynamics through tuning field frequency. Specifically, the domain wall velocity is proportional to the field frequency and the net angular momentum below the critical frequency, while it quickly decreases to zero above the critical frequency. The physical mechanisms of the results are discussed in detail, and the influences of the biaxial anisotropy and other parameters on the velocity of domain wall are explored. Thus, it is suggested that the domain wall dynamics can be effectively regulated by adjusting the basic magnetic structure and magnetic anisotropic, in addition to the external microwave field frequency. This work uncovers interesint dynamics of ferrimagnetic domain wall driven by sinusoidal microwave magnetic field, which is helpful for domain wall-based spintronic device design.