论文标题
带有垂直磁各向异性的纳米线旋转振荡器中的自旋波激发
Spin wave excitations in a nanowire spin-torque oscillator with perpendicular magnetic anisotropy
论文作者
论文摘要
自旋扭矩振荡器（STOS）是新兴的微波设备，可以在自旋逻辑设备和下一代高速计算体系结构中使用。由于它们的非线性性质，STOS很容易被磁场和直流电流调谐。自旋霍尔纳米振荡器（SHNOS）是有希望的STOS类型，而当前的大多数研究都集中在很容易激发的局部模式上。在这里，我们使用微磁模拟研究，这是用垂直磁各向异性（PMA）材料制成的纳米线设备中自旋刺激诱导的激发的性质。我们的结果表明，在包含PMA时，可行的局部和传播自旋波模式的激发是可行的。我们研究模式激发的性质是PMA强度（\ text {k} $ _ u $）和电流的函数。确实，我们估计\ text {k} $ _ u $的临界值，以激发传播自旋波。我们将本地化模式和传播模式之间的这种模式选择性归因于系统的非线性迹象，从负面到正的迹象，在非零\ text {k} $ _ u $下得到分析计算支持。我们的结果为未来的Magnonic和计算应用程序提供了对工程可重构的微波设备的深刻见解。
Spin torque oscillators (STOs) are emerging microwave devices that can potentially be used in spin-logic devices and the next-generation high-speed computing architecture. Thanks to their non-linear nature, STOs are easily tunable by the magnetic field and the dc current. Spin Hall nano-oscillators (SHNOs) are promising types of STOs and most of the current studies focus on localized modes that can be easily excited. Here, we study using micromagnetic simulations, the nature of the spin-torque-induced excitations in nanowire devices made of perpendicular magnetic anisotropy (PMA) material. Our results showed that upon including PMA the excitation of localized and propagating spin wave modes is feasible. We study the nature of the mode excitations as a function of the PMA strength (\text{K}$_u$), and the current. Indeed, we estimate a critical value of \text{K}$_u$ to allow for the excitation of the propagating spin wave. We attribute this mode selectivity between localized and propagating modes to a switch in the sign of the nonlinearity of the system from negative to positive at a non-zero \text{K}$_u$ which is supported by analytical calculations. Our results provide deep insight into engineering reconfigurable microwave devices for future magnonic and computational applications.
