自旋转移矩效应激发的非线性磁化动力学  

Nonlinear magnetization dynamics excited by the spin-transfer torque effect

作　　者：金伟[1,2] 万振茂[1] 刘要稳[1] 

机构地区：[1]同济大学物理系,上海200092 [2]安徽师范大学物理与电子信息学院,芜湖241000

出　　处：《物理学报》2011年第1期628-633,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50871075);教育部新世纪优秀人才基金(批准号:NCET-10-0603)资助的课题~~

摘　　要：本文基于宏观磁矩(macrospin)的Landau-Lifshitz-Gilbert方程,模拟研究了磁性自旋阀结构中由垂直膜面流向的自旋极化电流所激发的磁化转动动力学特性.直流自旋极化电流借助自旋转移矩效应可驱动磁矩翻转或作周期性振荡,交流电可以激发出具有混沌行为的磁矩振荡.展示了磁矩振荡行为随电流强度变化而发生倍周期分岔、直至混沌振荡的行为规律.The macrospin model based on Landau-Lifshitz-Gilbert equation is used to study the current-induced magnetization dynamics in magnetic spin valves. We find that the DC spin-polarized current could either switch the magnetization of free layer or excite the steady-state precessional motion via the so-called spin-transfer torque effect. The AC current could drive the chaotic oscillations. The route to chaotic oscillation depending on the strength of current is demonstrated through a series of period doubling bifurcations.

关 键 词：自旋转移矩效应 微磁模拟 磁性自旋阀 混沌 

分 类 号：O482.5[理学—固体物理]