Study On The Interaction Between Spin Wave And Domain Wall Dynamics On Magnetic Nanoribbons

Recently,domain wall(DW)motion in magnetic nanostripe have attracted much attention because of its potential applications to the next generation data storage and logic devices.Among these applications,the key technology is to manipulate DW propagation along the stripes.Up to now,there are four approaches to manipulate DW,i.e.,magnetic-field manipulation,spin-polarized-current manipulation,spin-wave(SW)manipulation and temperature-gradient manipulation.The spin-wave manipulation and spin-polarized-current manipulation are two hot spots concerned in theoretical study.Especially,the spin-wave manipulation has advantages of low consumption and avoiding the poor conductivity of magnetic materials.However,the underlying mechanism of SW-driven DW motion still have much controversy.It mainly includes two kinds of interpretation:spin transfer torque mechanism and linear momentum transfer torque.The direction of the domain wall motion depends on the frequency and amplitude of the spin wave.Moreover,the reflection and transmission coefficient of spin wave action to the domain wall are also an important factors.So on the one hand,the mechanism of spin transfer torque can not explain the direction of the propagation of spin wave.Another hand,When the spin wave propagate to the domain wall,according to Linear momentum transfer mechanism,it will be reflected or penetrated by the domain wall due to the conservation of momentum.However,when the spin wave propagate to the domain wall,the spin wave can interacts with the domain wall,but we still have not figure out what actually happens between domain wall and spin wave when spin wave arrived the domain wall.That is to say,the mechanism of interaction between the domain wall and spin wave is not very clear.Therefore,in this article,we research the static management of single domain wall and behavior of spin wave drive domain wall motion in the single magnetic nanostripe based on the method of micromagnetic simulation.The first chapter in this article we mainly introduces the origin of magnetism,the application and development of magnetic logic devices,and the knowledge of domain wall which including the ways to drive domain wall motion and the research situations of domain wall motion in theory and experiment.The second chapter introduces the method of micromagnetic simulation.Including the traditional spin dynamics method and the LLG equation with spin transfer torque.In the third chapter,we study the dynamics of a transverse wall(TW)driven by spin wave in a single magnetic nanostripe,focusing on the dynamical interaction between SW and TW.By micromagnetic simulations and we find that before SW reaches TW,TW oscillates naturally with a constant frequency,i.e.,a natural oscillation,whereas a forced oscillation is observed after SW acts on TW.Through tuning the frequency of SW,we confirm that the natural oscillation is independent of SW,and the forced one always has the same frequency as that of SW.Interestingly,the frequency-response curves of forced oscillations display multiple resonance peaks.Moreover,we find the frequency-response curves of force oscillation,SW reflection coefficient and TW velocity share the same multiple-resonance property,which may suggest the force-oscillation mechanism plays a important role in the SW-driven TW motion.The fourth chapter we discuss three different modes of spin wave with same power.Such that Triangular wave,square wave and sine wave.To understanding the mechanism of interaction between spin wave and domain wall in different modes and find out the effective method to control the wall motion,we focus on characteristics and rules of the spin wave driven domain wall motion in three different modes to provide theoretical guidance for the experiment.