Magnetic nano-oscillator driven by pure spin current
Magnetic nano-oscillator driven by pure spin current
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DOI：
10.1038/nmat3459
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发表时间：
2012-12-01
期刊：
影响因子：
41.2
通讯作者：
Demokritov, Sergej O.
中科院分区：
文献类型：
--
作者：
Demidov, Vladislav E.;Urazhdin, Sergei;Demokritov, Sergej O.
随着纯自旋电流源的出现，基于自旋的电子（自旋电子）设备不再需要电荷转移，为自旋电子系统的导电和绝缘开辟了新的可能性（1-9）。纯自旋电流已被用于抑制磁性纳米器件中由热波动引起的噪声，放大传播的磁化波，并减少磁膜中的动态阻尼（10-14）。然而，纯自旋电流产生相干自振荡迄今尚未实现。在这里，我们展示了在一个将纯自旋电流的局部注入与增强的自旋波辐射损失相结合的装置中产生单模相干自振荡。与直觉相反，辐射损耗能够激发自振荡，通过在不同模式之间重新分配能量来抑制防止自振荡的非线性过程（12,15）。我们的器件在中等电流密度下表现出自振荡，微波频率在很宽的范围内可调。这些发现为下一代集成电子学的纳米级微波源的实现提供了一条新的途径。
With the advent of pure-spin-current sources, spin-based electronic (spintronic) devices no longer require electrical charge transfer, opening new possibilities for both conducting and insulating spintronic systems(1-9). Pure spin currents have been used to suppress noise caused by thermal fluctuations in magnetic nanodevices, amplify propagating magnetization waves, and to reduce the dynamic damping in magnetic films(10-14). However, generation of coherent auto-oscillations by pure spin currents has not been achieved so far. Here we demonstrate the generation of single-mode coherent auto-oscillations in a device that combines local injection of a pure spin current with enhanced spin-wave radiation losses. Counterintuitively, radiation losses enable excitation of auto-oscillation, suppressing the nonlinear processes that prevent auto-oscillation by redistributing the energy between different modes(12,15). Our devices exhibit auto-oscillations at moderate current densities, at a microwave frequency tunable over a wide range. These findings suggest a new route for the implementation of nanoscale microwave sources for next-generation integrated electronics.