| The combination of spintronics and magnetic materials has greatly expanded the application of magnetic materials,and stimulated the research hotspots of information storage devices,logic devices and spintronics.In ferromagnetic materials,spin-orbit torque can effectively control the excitation of nonlinear waves,but its effects on solitons dynamics and other excited states have not been fully studied.Therefore,this thesis focuses on the study of analytical soliton solutions in anisotropic ferromagnetic lines under spin orbit torque,and analyzes their dynamic evolution properties in detail.Firstly,this paper introduces the research background and development status of spin-torque,including the theoretical and experimental research on the application of spin-torque to magnetic random access memory technology,and its potential application in the fields of information memory devices and logic devices.Secondly,the relationship between nonlinear excited states and stability analysis in magnetic systems is introduced.The modulation instability analysis derived from the excitation of pulse solitons in nonlinear optical fibers is an effective analysis method.On this basis,the linear stability analysis is used to analyze the spin waves in isotropic ferromagnet under the one-dimensional Heisenberg system,and the critical stability condition is determined.Finally,the modified Landau-Lifshitz-Gilbert equation describing the motion of magnetization is solved in detail by using the spherical pole mapping and the proposed method,and the analytical soliton solutions in the case of easy-axis and easy-plane anisotropy are obtained.These analytical results show that when the spin orbit torque increases,the width of the soliton decreases,while the precession frequency of the spin wave increases gradually.It is also found that the maximum deviation between the magnetization and the ground state is linear with the spin orbit torque,and is also affected by the Dzyaloshinskii-Moriya interaction. |
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