Boltzmann test of Slonczewski's theory of spin-transfer torque
Boltzmann test of Slonczewski's theory of spin-transfer torque
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DOI：
10.1103/physrevb.70.172405
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发表时间：
2004-11-01
影响因子：
3.7
通讯作者：
Stiles, MD
中科院分区：
文献类型：
--
作者：
Xiao, J;Zangwill, A;Stiles, MD
我们使用矩阵Boltzmann方程来检验SLonczewski的自旋转移扭矩理论在薄膜异质结构中的准确性，其中非磁性隔离层将连接到非磁性引线的两个非共线铁磁层分开。在适用的情况下，作为两个铁磁体之间夹角的函数的扭矩的模型预测与从玻尔兹曼方程计算得到的扭矩非常吻合。我们着重于非对称结构(其中两个铁磁体和两个引线不完全相同)，其中一致与我们使用SLonczewski理论导出的扭矩的解析公式有关。在几乎所有情况下，我们都可以直接从多层膜的几何和输运性质来预测模型参数的正确值。对于一些非对称几何，我们预测了一种稳定的进动模式，这在SLonczewski研究的对称情况下是不会发生的。
We use a matrix Boltzmann equation formalism to test the accuracy of Slonczewski's theory of spin-transfer torque in thin-film heterostructures where a nonmagnetic spacer layer separates two noncollinear ferromagnetic layers connected to nonmagnetic leads. When applicable, the model predictions for the torque as a function of the angle between the two ferromagnets agree extremely well with the torques computed from a Boltzmann equation calculation. We focus on asymmetric structures (where the two ferromagnets and two leads are not identical) where the agreement pertains to an analytic formula for the torque derived by us using Slonczewski's theory. In almost all cases, we can predict the correct value of the model parameters directly from the geometric and transport properties of the multilayer. For some asymmetric geometries, we predict a mode of stable precession that does not occur for the symmetric case studied by Slonczewski.