Large anomalous Hall effect and spin Hall effect by spin-cluster scattering in the strong-coupling limit
Large anomalous Hall effect and spin Hall effect by spin-cluster scattering in the strong-coupling limit
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DOI：
10.1103/physrevb.103.235148
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发表时间：
2021-06-23
影响因子：
3.7
通讯作者：
Nagaosa, Naoto
中科院分区：
文献类型：
--
作者：
Ishizuka, Hiroaki;Nagaosa, Naoto
扭曲散射--电子被杂质不对称散射--是引起反常/自旋霍尔效应的主要机制之一。尽管已知许多偏斜散射的微观机制，但这些机制产生的反常霍尔效应的霍尔角通常很小，通常为0.1度-1度。本文以强Kondo耦合机制为研究对象，研究了三自旋团簇的偏斜散射。利用T-矩阵形式，我们超越了以往研究中的微扰理论，计算了任意强度的Kondo耦合的散射几率。通过对单自旋、二自旋和三自旋团簇的散射几率的系统分析，我们发现在没有自旋-轨道相互作用的情况下，三个自旋是产生歪斜散射所必需的。当电子-自旋耦合与带宽相当时，三自旋团簇的偏斜散射产生约0.1prad量级的偏角(类似于18度)。我们还研究了反常/自旋霍尔效应与自旋手性的关系，认为即使在强耦合的情况下，反常-(自旋)霍尔斜角也与标量(净矢量)自旋手性近似成正比。这一机制可能与非中心对称和受阻磁体中的反常/自旋霍尔效应有关。
Skew scattering-an asymmetric scattering of electrons by impurities-is one of the major mechanisms causing anomalous/spin Hall effects. Although many microscopic mechanisms for skew scattering are known, the Hall angle of anomalous Hall effect by these mechanisms is often small, typically theta = 0.1 degrees - 1 degrees. In this paper, we study the skew scattering by three-spin clusters focusing on the strong Kondo-coupling regime. Using a T-matrix formalism, we calculate the scattering probability for arbitrary strength of Kondo coupling, going beyond perturbation theory in previous studies. From a systematic analysis of the scattering probability for one-, two-, and three-spin clusters, we show that three spins are necessary for the skew scattering in the absence of spin-orbit interaction. The skew scattering by the three-spin cluster produces a skew angle on the order of 0.1 pi rad (similar to 18 degrees) when the electron-spin coupling is comparable to the bandwidth. We also study the relationship between the anomalous/spin Hall effects and the spin chiralities and argue that the anomalous-(spin) Hall skew angle is approximately proportional to the scalar (net vector) spin chirality even for the strong-coupling cases. This mechanism is potentially relevant to anomalous/spin Hall effects in noncentrosymmetric and frustrated magnets.