利用非共线磁性双层膜研究光激发太赫兹自旋驻波
Investigating optically-excited THz standing spin waves using noncollinear magnetic bilayers
摘要：
我们研究了非共线磁性双层膜中的光激发太赫兹自旋驻波。使用飞秒激光脉冲激励，在第一铁磁（FM）层中产生自旋电流，并且该自旋电流流过导电间隔层以被注入到第二（横向）FM层中，在第二（横向）FM层中，该自旋电流对磁化施加自旋转移力矩并且激励高阶自旋驻波。我们表明，非共线磁性双层是一个方便的工具，可以很容易地激发太赫兹自旋波，并可用于调查的色散，从而在薄膜制度的自旋波刚度参数。这是实验证明使用楔形的Co和CoB（吸收）层。此外，这些太赫兹自旋波的阻尼进行了研究，表现出强烈的阻尼增加，减少吸收层的厚度，比预期的界面自旋泵效应强得多。此外，观察到一个以前看不见的突然下降的阻尼最薄的薄膜。提出了一个模型，将这两个观测的额外阻尼的贡献。
英文摘要：
We investigate optically excited THz standing spin waves in noncollinear magnetic bilayers. Using femtosecond laser-pulse excitation, a spin current is generated in the first ferromagnetic (FM) layer, and flows through a conductive spacer layer to be injected into the second (transverse) FM layer, where it exerts a spin-transfer torque on the magnetization and excites higher-order standing spin waves. We show that the noncollinear magnetic bilayer is a convenient tool that allows easy excitation of THz spin waves, and can be used to investigate the dispersion and thereby the spin wave stiffness parameter in the thin-film regime. This is experimentally demonstrated using wedge-shaped Co and CoB (absorption) layers. Furthermore, the damping of these THz spin waves is investigated, showing a strong increase of the damping with decreasing absorption layer thickness, much stronger than expected from interface spin pumping effects. Additionally, a previously unseen sudden decrease in the damping for the thinnest films is observed. A model for the additional damping contribution incorporating both these observations is proposed.
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。
