arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.09737cond-mat.mes-hallcond-mat.mtrl-sci
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自旋霍尔纳米振荡器中自旋波的电激发和操纵研究进展

Recent Progress on Electrical Excitation and Manipulation of Spin-Waves in Spin Hall Nano-Oscillators

Liyuan Li, Lina Chen, Ronghua Liu, Youwei Du

摘要:

自旋波(SW),集体旋进运动的自旋在磁系统中,已被提出作为一个有前途的替代系统与低功耗的信息编码。自旋霍尔纳米振荡器(SHNO)是一种新型自旋电子纳米器件,它可以在纳米磁性金属和绝缘体中电激发和控制自旋波,并且由于自旋霍尔效应产生的自旋电流对自旋波的阻尼很低。本文综述了SHNOs中自旋波激发和光谱与实验参数关系的最新进展。基于面内磁化Py/Pt的纳米间隙SHNO表现出非线性的自局域子弹孤子和次级高频模式,该模式在较高电流下与初级子弹模式共存。而在具有强垂直磁各向异性(PMA)的纳米间隙SHNOs中,除了可以通过改变外加磁场和电流来实现和控制非线性子弹孤子和自旋波传播模式外,还可以在较低的面内磁场下激发磁泡skyrmion模式。这些SW模式在高温下由于热磁振子介导的散射介导的模式之间的耦合而表现出热诱导模式跳跃行为。此外,由于PMA诱导的有效场,也可以在不施加外部磁场的情况下实现单个相干模式。自旋波的强非线性效应使得SHNO易于实现与外部微波信号的同步或多个振荡器之间的相互同步,从而显著提高振荡模式的相干性和功率。具有外部自由磁性层的SHNO中的自旋波具有广泛的应用,从作为低功耗磁振子器件的纳米级信号源到人工智能领域中的基于自旋的神经形态计算系统。

英文摘要:

Spin waves (SWs), the collective precessional motion of spins in a magnetic system, have been proposed as a promising alternative system with low-power consumption for encoding information. Spin Hall nano-oscillator (SHNO), a new-type spintronic nano-device, can electrically excite and control spin waves in both nanoscale magnetic metals and insulators with low damping by the spin current due to spin Hall effect. Here, we will review recent progress about spin-wave excitation and experimental parameters dependent spectrum in SHNOs. The nanogap SHNOs based on in-plane magnetization Py/Pt exhibits a nonlinear self-localized bullet soliton localized at the center of the gap between the electrodes and a secondary high-frequency mode which coexists with the primary bullet mode at higher currents. While in the nanogap SHNOs with strong perpendicular magnetic anisotropy (PMA), besides both nonlinear bullet soliton and propagating spin-wave mode are achieved and controlled by varying the external magnetic field and current, the magnetic bubble skyrmion mode also can be excited at a low in-plane magnetic field. These SW modes show thermal-induced mode hopping behavior at high temperature due to the coupling between modes mediated by thermal-magnon-mediated scattering. Moreover, thanks to PMA-induced effective field, a single coherent mode also can be achieved without applying an external magnetic field. The strong nonlinear effect of spin-waves makes SHNOs easy to achieve synchronization with external microwave signals or mutual synchronization between multiple oscillators with improving the coherence and power of oscillation modes significantly. Spin-waves in SHNOs with an external free magnetic layer have a wide range of applications from as a nanoscale signal source of low-power consumption magnonic devices to spin-based neuromorphic computing systems in the field of artificial intelligence.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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