Giant spin-accumulation signal and pure spin-current-induced reversible magnetization switching
Giant spin-accumulation signal and pure spin-current-induced reversible magnetization switching
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DOI：
10.1038/nphys1095
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发表时间：
2008-11-01
期刊：
影响因子：
19.6
通讯作者：
Otani, Yoshichika
中科院分区：
文献类型：
--
作者：
Yang, Tao;Kimura, Takashi;Otani, Yoshichika
许多提出的下一代电子器件，包括新颖的存储器元件（1）和多功能晶体管电路（2），依赖于自旋电流，即电子角动量的流动。自旋电流可以与磁性纳米结构相互作用，并产生自旋相关的传输现象，或激发磁化动力学（1-11）。与自旋极化电荷电流相反，纯自旋电流不会产生任何与电荷相关的寄生效应（12，13）。产生纯自旋电流的一种方法是非局域电自旋注入（12-18），但这种方法迄今为止一直存在注入效率低的问题。在这里，我们证明了一个显着的增强的非本地注入效率在横向自旋阀准备与完全原位制造工艺。界面质量和器件结构的改善导致自旋信号幅度增加了一个数量级。所产生的纯自旋电流使得能够以与使用充电电流的情况相同的效率实现纳米磁体的磁化反转。这些结果对于多终端结构（2）的进一步理论发展非常重要，而且对于实现由纯自旋电流驱动的新型器件也很重要。
A number of proposed next-generation electronic devices, including novel memory elements(1) and versatile transistor circuits(2), rely on spin currents, that is, the flow of electron angular momentum. A spin current may interact with a magnetic nanostructure and give rise to spin-dependent transport phenomena, or excite magnetization dynamics(1-11). In contrast to a spin-polarized charge current, a pure spin current does not produce any charge-related spurious effects(12,13). One way to produce a pure spin current is non-local electrical-spin injection(12-18), but this approach has suffered so far from low injection efficiency. Here, we demonstrate a significant enhancement of the non-local injection efficiency in a lateral spin valve prepared with an entirely in situ fabrication process. Improvements to the interface quality and the device structure lead to an increase of the spin-signal amplitude by an order of magnitude. The generated pure spin current enables the magnetization reversal of a nanomagnet with the same efficiency as in the case of using charge currents. These results are important for further theoretical developments in multi-terminal structures(2), but also with a view towards realizing novel devices driven by pure spin currents.