Spin-caloric phenomena in suspended ferromagnets: from plane film to low-dimensional effects

铁磁体中由温度梯度引起的自旋输运现象引起了磁学研究的极大兴趣。在这里，对最近发现的自旋塞贝克效应的基本理解提出了一个巨大的挑战。我们建议研究铁磁器件中的热致自旋输运现象，这些器件是悬浮的，即与衬底解耦。这将允许我们创建大的温度梯度，并接近考虑热和自旋流的一维方法的理论模型。我们将修改传输性质，例如，通过狭窄的收缩或周期性的空穴阵列来纳米刻画铁磁体。我们将进一步考虑非均匀磁化模式和磁畴壁。通过这些方法，我们将解决一个开放的问题，即声子(晶格振动)、磁子(集体自旋激发)、电子和自旋流在什么程度上与热感应电信号相关并做出贡献。

Spin transport phenomena induced by thermal gradients in a ferromagnet have generated a large interest in magnetism research. Here, the fundamental understanding of the recently discovered spin Seebeck effect presents a great challenge. We propose to investigate heat-induced spin transport phenomena in ferromagnetic devices which are suspended, i.e., decoupled from the substrate. This will allow us to create large thermal gradients and come close to theoretical models considering a onedimensional approach for heat and spin-current flow. We will modify the transport properties in that we nanopattern the ferromagnet by, e.g., narrow constrictions or periodic arrays of holes. We will further consider inhomogeneous magnetization patterns and domain walls. By these means we will address the open question to which degree phonons (lattice vibrations), magnons (collective spin excitations), electron and spin currents are relevant and contribute to the heat-induced electrical signals.