Magnetodynamics in orthogonal nanocontact spin-torque nano-oscillators based on magnetic tunnel junctions
Magnetodynamics in orthogonal nanocontact spin-torque nano-oscillators based on magnetic tunnel junctions
复制标题
DOI：
10.1063/1.5121356
复制
发表时间：
2019-07
影响因子：
4
通讯作者：
Sheng Jiang;M. Ahlberg;Sunjae Chung;A. Houshang;Ricardo Ferreira;Paulo P. Freitas;J. Åkerman
中科院分区：
文献类型：
--
作者：
Sheng Jiang;M. Ahlberg;Sunjae Chung;A. Houshang;Ricardo Ferreira;Paulo P. Freitas;J. Åkerman
我们展示了基于正交磁性隧道结（MTJ）的纳米接触自旋扭矩纳米振荡器（STNO）中的场和电流控制的磁动力学。我们系统地分析了微波特性（频率$f$、线宽$\Delta f$、功率$P$以及频率可调性$df/dI$）及其物理根源——垂直磁各向异性（PMA）、类阻尼和类场自旋转移扭矩（STT）以及压控磁各向异性（VCMA）。这些器件具有几个优势特性：高发射频率（$f>20$GHz）、高频率可调性（$df/dI = 0.25$~GHz/mA）以及零场操作（$f\sim4$GHz）。此外，对$f(H, I)$的详细研究表明，$df/dI$主要由大的VCMA（287~fJ/(V·m)）决定，而STT的作用可忽略不计。
We demonstrate field and current controlled magnetodynamics in nanocontact spin-torque nano-oscillators (STNOs) based on orthogonal magnetic tunnel junctions (MTJs). We systematically analyze the microwave properties (frequency $f$, linewidth $\Delta f$, power $P$, and frequency tunability $df/dI$) with their physical origins---perpendicular magnetic anisotropy (PMA), damping-like and field-like spin transfer torque (STT), and voltage-controlled magnetic anisotropy (VCMA). These devices present several advantageous characteristics: high emission frequencies ($f> 20$ GHz), high frequency tunability ($df/dI=0.25$~GHz/mA), and zero-field operation ($f\sim 4$ GHz). Furthermore, a detailed investigation of $f(H, I)$ reveals that $df/dI$ is mostly governed by the large VCMA (287~fJ/(V$\cdot$m)), while STT plays a negligible role.