The Numerical Model of Magnetic Switching by Spin Hall Effect

• Main Authors: LIN,YI-TSUNG, 林乙璁
• Other Authors: CHERN,GUNG
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/63453748123543685432

碩士 === 國立中正大學 === 物理系研究所 === 104 === In this thesis, we study magnetization switching by spin Hall effect (SHE), which is induced by in-plane injected currents for the single magnetic layer system or the double magnetic layers system with perpendicularly anisotropic. We use the Landau–Lifshitz–Gilbert (LLG) equation to simulate the time evolution of magnetization and compare the result with experimental observations. The obtained results are mainly divided into three parts: (1) Simulations of the magnetic switching by introducing a tilted uniaxial perpendicular magnetic anisotropy ,varying injected currents with a fixed in-plane magnetic field. We discuss how magnetic moment precess with the LLG equation in terms of damping torque and Anti-damping torque for predictions for current-induced magnetic switching. (2) Simulations of varying applied magnetic fields with a fixed injected current for the single magnetic layer system. We simulate the dependence of hysteresis loops on different positive (negative) current densities. We obtain the coercivity (Hc) via analysis and make a comparison between simulations and experimental data. (3) Simulations of varying applied magnetic fields with a fixed injected current for the double magnetic layer systems. By introducing an antiferromagnetic coupling term in the LLG equation,the magnetic state of Y-axis can be found out easier than the single magnetic layer system.The comparison between simulations and experimental data are performed for the present system.