来自自旋群对称性的共线铁磁体中的自旋霍尔效应
Spin Hall Effect in Collinear Ferromagnets from Spin-Group Symmetry
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中文总结 AI 辅助
研究共线铁磁体中自旋霍尔效应的微观起源，通过将自旋轨道耦合视为破坏自旋群对称性的微扰进行分析，识别出不同阶次的自旋霍尔效应机制，经第一性原理计算证实，为自旋电子学应用提供了理论基础。
中文摘要 AI 辅助
磁性材料支持时间反演偶（T-偶）和时间反演奇（T-奇）自旋霍尔电流，但其微观起源仍不明确。本文通过将自旋轨道耦合（SOC）视为破坏自旋群对称性的微扰，阐明共线铁磁体中的自旋霍尔效应（SHE），揭示磁序如何激活不同的自旋霍尔响应。在SOC一阶，识别出两种主要的T-偶SHE机制及主导的T-奇磁自旋霍尔效应（MSHE）起源。在SOC二阶，发现独特的T-奇平面自旋霍尔机制。第一性原理计算证实了自旋对称性分析，揭示出显著的各向异性磁自旋霍尔效应。这些发现阐明了共线铁磁体中自旋霍尔电导率（SHC）的微观起源，为自旋电子学应用中具有多功能特性的基于铁磁体的自旋电流源铺平了道路。
英文摘要
Magnetic materials support both time-reversal-even (T-even) and time-reversal-odd (T-odd) spin Hall currents, yet their underlying microscopic origins remain elusive. Here, we elucidate the spin Hall effect (SHE) in collinear ferromagnets by treating spin-orbit coupling (SOC) as a perturbation that breaks spin-group symmetry, thereby revealing how magnetic order activates distinct spin Hall response. To first order in SOC, we identify two dominant T-even SHE mechanisms: a magnetization-independent conventional contribution and a magnetization-dependent channel associated with anomalous Hall charge transport. At the same order, the leading T-odd magnetic spin Hall effect (MSHE) originates from the exchange interaction between the conventional spin current and the local magnetization. At second order in SOC, we further uncover a distinct T-odd planar spin Hall mechanism. Our spin-symmetry analysis is corroborated by first-principles calculations, which reveal a pronounced anisotropic magnetic spin Hall effect whose magnitude can be comparable to the T-even spin Hall conductivity (SHC) when the magnetic moment is tilted away from the principal crystallographic axes. These findings clarify the microscopic origins of the SHC in collinear ferromagnets and pave the way for ferromagnet-based spin current sources with versatile properties in spintronic applications.
