Spin current effects in nanostructured films

该项目的重点将是自旋电流效应在图案磁结构。我们建议根据结构的形状来研究磁激励的本征模式。在使用钛蓝宝石激光脉冲作为频闪手电筒的全光泵和探针实验中，特殊模式的选择和操纵能达到什么程度？激励泵脉冲产生非平衡状态。弛豫过程中的散射过程导致自旋系统与三温度模型中描述的热化电子系统的耦合，并触发相干和非相干磁化动力学。正如我们在微磁模拟中看到的，~5-10%的相当小的退磁效应激发了自旋系统的基本模式。模态受偶极场的强烈支配。这个项目的重点将是研究自旋电流在层状系统界面上从这种非平衡状态演变而来。自旋电流效应以两种方式进入自旋系综的复杂动力学：首先，自旋系统的相干进动在邻近的非磁性金属层中激发自旋电流。这作为一个额外的阻尼依赖于自旋轨道散射。其次，注入磁性结构的自旋电流通过保持总角动量来启动自旋系统的进动。这两种影响将在拟议的项目中进行研究。

Focus of the project will be spin current effects in patterned magnetic structures. We propose to investigate the eigen modes of magnetic excitations depending on the shape of the structures. In how far can special modes be selected and manipulated in an all optical pump and probe experiment using a Ti:sapphire laser pulse as a stroboscopic flashlight? The exciting pump pulse generates a nonequilibrium situation. Scattering processes during the relaxation process result in a coupling of the spin system with the thermalizing electron system as described in the three temperature model, and triggers coherent and non coherent magnetization dynamics. Rather small demagnetization effects of ~5-10% excite fundamental modes of the spin system as we have seen in micromagnetic simulations. The modes are strongly dominated by dipolar fields. Focus of this project will be the study of spin currents evolving from this nonequilibrium situation at the interfaces of layered systems. Spin current effects enter in the complex dynamics of the spin ensemble in two ways: Firstly, the coherent precession of a spin system excites a spin current in an adjacent nonmagnetic metallic layer. This acts as an additional damping dependent on the spin orbit scattering. Secondly, spin currents injected into a magnetic structure start a precession of the spin system by conserving the total angular momentum. Both effects will be studied within the proposed project.