摘要
提出了一个基于磁动力学方程的宏观唯象理论模型,对纳米级赝自旋阀结构的电流感应磁化翻转效应给出了明晰的物理解释:流入自由层的净自旋流和自由层内的自旋弛豫过程的共同作用,导致自由层总磁矩随时间的改变,甚至产生磁化方向的翻转.模型将“铁磁/非铁磁”界面的自旋相关散射,以及铁磁层中的自旋积累和弛豫过程,统一于宏观的磁动力学方程中.通过求解该方程的解析解,给出了赝自旋阀在电流激励下的磁化翻转条件和临界电流密度的表达式.对该效应的定性解释和数值模拟结果都和实验报道良好符合.根据模型分析了影响临界电流密度的诸因素,并指出提高器件性能的途径.
A macroscopic phenomenological model based on the magnetic dynamic equation was proposed to investigate spin-polarized current induced magnetization switching in a nano-scale pseudo-spin-valve structure. The movement and even reversal of the free layer＇s magnetization resulted from two factors, the net spin flux flowing into the free layer and the spin relaxation within it. The dynamic equation incorporated the spin-dependent scattering at the ferromagnetics/nonmagnetics interfaces, and the relaxation of spin accumulation in the ferromagnetic layer. Conditions of magnetization reversal and the corresponding critical currents were found by solving the dynamic equation analytically. The qualitative and quantitative results agree with most of experiments reported. According to the model, the influencing factors on the critical current were analyzed and the methods to improve device performances were pointed out.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第5期2863-2867,共5页
Acta Physica Sinica
基金
国家自然科学基金(批准号:60606021)
高等学校博士学科点专项科研基金(批准号:20060003067)
清华大学基础研究重点基金(批准号:Jz2001010)资助的课题~~
关键词
电流感应磁化翻转
磁动力学方程
自旋电子学
current induced magnetization switching, magnetic dynamic equation, spintronics
