Mechanism of paramagnetic spin Seebeck effect
Mechanism of paramagnetic spin Seebeck effect
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顺磁自旋塞贝克效应的机理
DOI：
10.1103/physrevb.107.014423
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发表时间：
2023
影响因子：
3.7
通讯作者：
Saitoh Eiji
中科院分区：
文献类型：
--
作者：
Oyanagi Koichi;Takahashi Saburo;Kikkawa Takashi;Saitoh Eiji
本文从理论上研究了正常金属（NM）/顺磁绝缘体（PI）双层膜系统中的自旋塞贝克效应（SSE）。通过线性响应方法，我们计算了PI到NM的热自旋抽运和NM到PI的自旋回流，其中考虑了NM中的传导电子自旋和PI中的局域自旋之间的界面交换耦合引起的自旋翻转散射.我们发现在NM和PI中自旋的有效温度不同的情况下，在界面处出现有限的自旋流，并且其强度随着局域自旋密度的增加而增加。我们的模型很好地再现了磁场诱导的顺磁SSE减少Pt/实验观察到的塞曼能量是可比的热能，这可以解释为抑制的界面自旋翻转散射。本研究结果提供了一个洞察顺磁性SSEs和热致自旋电流产生的磁性材料的机制。
We have theoretically investigated the spin Seebeck effect (SSE) in a normal metal (NM)/paramagnetic insulator (PI) bilayer system. Through a linear response approach, we calculated the thermal spin pumping from PI to NM and backflow spin current from NM to PI, where the spin-flip scattering via the interfacial exchange coupling between conduction-electron spin in NM and localized spin in PI is taken into account. We found a finite spin current appears at the interface under the difference in the effective temperatures between spins in NM and PI, and its intensity increases by increasing the density of the localized spin. Our model well reproduces the magnetic-field-induced reduction of the paramagnetic SSE in Pt/experimentally observed when the Zeeman energy is comparable to the thermal energy, which can be interpreted as the suppression of the interfacial spin-flip scattering. The present finding provides an insight into the mechanism of paramagnetic SSEs and the thermally induced spin-current generation in magnetic materials.