Ultrafast spin exchange-coupling torque via photo-excited charge-transfer processes.
Ultrafast spin exchange-coupling torque via photo-excited charge-transfer processes.
复制标题
通过光激发电荷转移过程实现超快自旋交换耦合扭矩
DOI：
10.1038/ncomms9800
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发表时间：
2015-10-28
影响因子：
16.6
通讯作者：
Lüpke G
中科院分区：
文献类型：
--
作者：
Ma X;Fang F;Li Q;Zhu J;Yang Y;Wu YZ;Zhao HB;Lüpke G
自旋的光学控制在利用短时间尺度自旋动力学研究超快自旋电子器件中具有重要意义。近年来发展起来的光学方法如超快退磁、自旋转移和自旋-轨道矩等为通过自旋与光子、轨道、电荷或声子的相互作用来操纵自旋开辟了新的途径。然而，这些方法受到长的热恢复时间或低温要求的限制。在这里，我们实验证明了超快相干自旋进动通过光学电荷转移过程中的交换耦合Fe/CoO系统在室温下。自旋旋进激励的效率显著更高，并且交换耦合扭矩的恢复时间比去磁过程短得多，这对于快速切换是期望的。交换耦合是自旋阀和隧道结中的一个关键问题，因此我们的研究结果将有助于促进超快相干自旋操纵交换耦合器件概念的发展。
Optical control of spin is of central importance in the research of ultrafast spintronic devices utilizing spin dynamics at short time scales. Recently developed optical approaches such as ultrafast demagnetization, spin-transfer and spin-orbit torques open new pathways to manipulate spin through its interaction with photon, orbit, charge or phonon. However, these processes are limited by either the long thermal recovery time or the low-temperature requirement. Here we experimentally demonstrate ultrafast coherent spin precession via optical charge-transfer processes in the exchange-coupled Fe/CoO system at room temperature. The efficiency of spin precession excitation is significantly higher and the recovery time of the exchange-coupling torque is much shorter than for the demagnetization procedure, which is desirable for fast switching. The exchange coupling is a key issue in spin valves and tunnelling junctions, and hence our findings will help promote the development of exchange-coupled device concepts for ultrafast coherent spin manipulation.