Spin transport at interfaces with spin-orbit coupling: Formalism
Spin transport at interfaces with spin-orbit coupling: Formalism
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DOI：
10.1103/physrevb.94.104419
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发表时间：
2016-09-16
影响因子：
3.7
通讯作者：
Stiles, M. D.
中科院分区：
文献类型：
--
作者：
Amin, V. P.;Stiles, M. D.
我们推广了磁电子电路理论来解释通过界面自旋轨道耦合的自旋向原子晶格的转移和从原子晶格的自旋转移。这使得能够适当地处理铁磁体和重金属非磁体之间界面处的自旋输运。这种广义的方法用界面上的自旋和电荷积累中的液滴来描述自旋输运(如在标准方法中)，但另外还包括面内电场和自旋积累中的偏移量的响应。一个关键的发现是，面内电场引起自旋积累和自旋流，可以在任何方向极化，推广了拉什巴-埃德尔斯坦效应和自旋霍尔效应。当自旋累积偏离磁化方向时，它们会对界面的磁化施加扭矩。附加的面外自旋电流通过铁磁层上的自旋转移机制施加扭矩。为了解释这些现象，我们还在广义电路理论中描述了自旋力矩。这个广义电路理论中包含的附加效应表明，对涉及自旋轨道扭矩、自旋泵浦、自旋记忆损失、拉什巴-埃德尔斯坦效应和自旋霍尔磁阻的实验的解释是错误的。
We generalize magnetoelectronic circuit theory to account for spin transfer to and from the atomic lattice via interfacial spin-orbit coupling. This enables a proper treatment of spin transport at interfaces between a ferromagnet and a heavy-metal nonmagnet. This generalized approach describes spin transport in terms of drops in spin and charge accumulations across the interface (as in the standard approach), but additionally includes the responses from in-plane electric fields and offsets in spin accumulations. A key finding is that in-plane electric fields give rise to spin accumulations and spin currents that can be polarized in any direction, generalizing the Rashba-Edelstein and spin Hall effects. The spin accumulations exert torques on the magnetization at the interface when they are misaligned from the magnetization. The additional out-of-plane spin currents exert torques via the spin-transfer mechanism on the ferromagnetic layer. To account for these phenomena we also describe spin torques within the generalized circuit theory. The additional effects included in this generalized circuit theory suggest modifications in the interpretations of experiments involving spin-orbit torques, spin pumping, spin memory loss, the Rashba-Edelstein effect, and the spin Hall magnetoresistance.