Exploring the thermoelectric properties of normal/ferromagnetic interfaces using current heating techniques

在这个项目中，我们建议详细研究热电现象的性质，在正常/铁磁界面使用电流加热技术，局部应用热梯度。我们的材料选择这项工作将是铁磁半导体（Ga，Mn）的原因有两个。首先，全半导体器件比金属结更适合于测量扩散热电势（与声子拖曳不同）所需的电流加热技术，其次，正如我们的初步工作已经表明的那样，这种材料中的强自旋轨道耦合，将磁性与态密度耦合，导致了丰富的热电势现象。例如，我们的初步研究已经揭示了热电塞贝克效应中的强隧穿各向异性磁热电势。我们期望发现和详细探索所有的热电和热磁效应，如能斯特，Ettinghausen和Righi-Leduc的异常和各向异性的贡献。应该强调的是，虽然（Ga，Mn）As是我们研究的理想材料，但这里研究的效应绝不限于半导体领域，并且确实在所有磁性材料中都很重要，但特别是那些具有强自旋轨道耦合的材料，例如CoPt多层膜。

In this project we propose to study in detail the nature of thermoelectric phenomena at normal/ferromagnetic interface using current heating techniques to locally apply the heat gradient. Our material of choice for this work will be the ferromagnetic semiconductor (Ga,Mn)As for two reasons. First, an all semiconductor device is much more appropriate for the current heating techniques needed to measure the diffusive thermopower (distinct from the phonon drag) than would be metallic junctions, and second, as our preliminary work already shows, the strong spin orbit coupling in this material, which couples the magnetic properties to the density of states, leads to a rich phenomenology of thermopower. Our preliminary studies have, for example, already revealed a strong tunneling anisotropic magneto-thermopower in the thermoelectric Seebeck effect. We expect to find and explore in detail anomalous and anisotropic contributions in all the thermoelectric and thermomagnetic effects such as Nernst, Ettinghausen and Righi-Leduc. It should be emphasized that while (Ga,Mn)As is the ideal material for our investigations, the effects studied here are by no means confined to the realm of semiconductors, and indeed will be important in all magnetic materials, but in particular those with strong spin orbit coupling, such as for example, CoPt multilayers.