Magnon Spin Hall Effect

基于绝缘体的自旋电子学的实现，与纯自旋电流完美地从电子电流解耦，可能提供了从传统的耗散限制电子学到根本不同的信号传输范例的基础。在磁性绝缘体（或铁氧体）中，自旋角动量可以通过磁振子转移，磁振子是毫米距离上的自旋波量子。自旋泵现象（在自旋波和常规自旋流之间提供桥梁）与自旋霍尔效应（在常规自旋流和电子流之间提供桥梁）一起对于该领域的进一步发展至关重要。我们的研究将集中在自旋波或磁振子的产生，检测和放大的机制，通过电子流使用的直接和逆自旋霍尔效应。时间，空间和波矢分辨布里渊光散射光谱以及微波技术将被用来详细研究这些影响。研究自旋波频率、波矢、群速度和相位相干性对自旋抽运效率的影响，将为磁绝缘体/金属磁介质系统的自旋抽运提供新的认识。一个特别的重点将在于使用自旋霍尔效应的自旋波的放大。此外，这项工作将在基于磁振子的自旋电子学的发展及其与传统电子学的集成方面建立里程碑。

The realization of insulator-based spintronics, operating with pure spin currents perfectly decoupled from electron currents, potentially provides the basis for a move away from conventional dissipation- limited electronics to a fundamentally different signal-transfer paradigm. In magnetic insulators (or ferrites) spin angular momentum can be transferred by magnons, the quanta of spin waves over millimetre distances. Spin pumping phenomena (which provide a bridge between spin waves and conventional spin currents) together with the spin Hall effect (which provides a bridge between conventional spin currents and electron currents) are of paramount importance for the further development of this field. Our study will focus on the mechanisms of generation, detection, and amplification of spin waves or magnons by electron currents using both the direct and inverse spin Hall effects. Time-, space- and wavevector-resolved Brillouin light scattering spectroscopy as well as microwave techniques will be used to study these effects in detail. The investigation of the influence of spin-wave frequency, wavevector, group velocity and phase coherency on the spin pumping efficiency will provide new understanding of spin pumping in magnetic insulator/ nonmagnetic metal systems. A particular focus will lie on the amplification of spin waves using the spin Hall effect. In addition, the work will establish milestones in the development of magnonbased spintronics and its integration with conventional electronics.