论文标题
顺磁性旋转塞贝克效应的机理
Mechanism of paramagnetic spin Seebeck effect
论文作者
论文摘要
我们从理论上研究了正常金属（NM）/顺磁绝缘体（PI）双层系统中的自旋塞贝克效应（SSE）。通过线性响应方法，我们计算了从PI到NM的热自旋泵送，并从NM到PI进行了回流旋转电流，在该电流中通过界面交换的旋转散射在NM中的传导 - 电子自旋之间的界面交换耦合，并考虑了PI中局部旋转的旋转。我们发现，在NM和PI中旋转之间有效温度的差异下，界面处出现有限的自旋电流，其强度通过增加局部旋转$ S $的密度而增加。我们的模型很好地重现了PT/gd $ _3 $ ga $ _5 $ _5 $ o $ $ _ {12} $实验观察到的Zeeman Energy可与热能可比的实验观察到的磁场引起的磁场诱导的降低，这可以解释为抑制interfial Spin-Spin-Flip散射。本发现提供了对磁性材料中顺磁性SSE的机理和热诱导的自旋产生的见解。
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 $S$. Our model well reproduces the magnetic-field-induced reduction of the paramagnetic SSE in Pt/Gd$_3$Ga$_5$O$_{12}$ 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.
