Faculty of Physics, Warsaw University of Technology, Koszykowa 75, PL-00-662 Warsaw, Poland.
J Phys Condens Matter. 2011 Nov 16;23(45):456001. doi: 10.1088/0953-8984/23/45/456001. Epub 2011 Oct 21.
The thermopower, charge and thermal conductance, and figure of merit as well as the spin-transfer torque generated by the temperature gradient in the planar tunnel junction consisting of ferromagnetic layers and the nonmagnetic tunnel barrier are investigated in the free-electron-like spin-polarized one-band model. In particular, the influence of the parameters of the junction as well as the influence of the relative orientation of magnetic moments on the studied phenomena are investigated. The thermopower can be related to the voltage drop generated by the temperature difference between electrodes under the condition that the charge current vanishes. It depends on the magnetic configuration of the junction. In junctions with high barriers the thermopower is maximal in the antiparallel configuration and it can be enhanced in junctions with strong spin-splitting of the electron bands. The component of the torque studied in the present paper is oriented in the plane formed by magnetic moments and it appears in the absence of the bias voltage. Its magnitude is insensitive to the sign of the temperature difference in contrast to the bias-induced in-plane torque which strongly depends on the polarization of the bias. The studied torque is usually smaller than the torque generated by the bias: however, it can be significant in junctions with low barriers.
在自由电子型自旋极化单带模型中，研究了由铁磁层和非磁隧道势垒组成的平面隧道结中的热功率、电荷和热导率以及优值，以及温度梯度产生的自旋转移扭矩。特别是，研究了结的参数以及磁矩相对取向对所研究现象的影响。在电荷电流为零的情况下，温差产生的电压降可以与热功率相关。它取决于结的磁构型。在高势垒结中，反平行构型的热功率最大，并且在电子能带的自旋劈裂较强的结中可以增强。本文研究的扭矩分量在由磁矩形成的平面中定向，并且在没有偏置电压的情况下出现。与偏置诱导的面内扭矩相比，其大小对温差的符号不敏感，而偏置诱导的面内扭矩强烈依赖于偏置的极化。所研究的扭矩通常比由偏置产生的扭矩小：但是，在低势垒结中可能很重要。
