Spin torque driven excitations in a synthetic antiferromagnet
Spin torque driven excitations in a synthetic antiferromagnet
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DOI：
10.1063/1.3314282
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发表时间：
2010-02-15
影响因子：
4
通讯作者：
Maas, W.
中科院分区：
文献类型：
--
作者：
Houssameddine, D.;Sierra, J. F.;Maas, W.
研究了自旋极化电流在自旋阀纳米柱的自由层和人工反铁磁（SAF）钉住层中诱导的自激振荡。与自由层激励相比，声型SAF激励具有发射功率高、线宽窄的特点。此外，与自由层激励相比，随着面内磁场的增加，SAF面内进动模式在频率f与电流I之间表现出意想不到的从红移（df/dI < 0）到蓝移（df/dI>）的交叉。从模拟中，我们确定这种交叉是SAF中大振幅自旋电流诱导的岁差动力学的特征。
Spin polarized current induced self oscillations have been investigated in both the free layer and the synthetic antiferromagnetic (SAF) pinned layer of spin valve nanopillars. Compared with free layer excitations, the acoustic type SAF excitations are characterized by high emitted power and much narrower linewidth. Furthermore, in contrast to free layer excitations, the SAF in-plane precession mode exhibits an unexpected crossover from redshift (df/dI < 0) to blueshift (df/dI>0) in frequency f versus current I as the in-plane magnetic field is increased. From simulations we identify this crossover as a signature of large amplitude spin current induced precessional dynamics in the SAF.