WikiEdge:ArXiv速递/2025-02-28

摘要

• 原文标题：Eightfold Degenerate Dirac Nodal Line in Collinear Antiferromagnet Mn$_5$Si$_3$
• 中文标题：共线反铁磁体Mn$_5$Si$_3$中的八重简并狄拉克节线
• 发布日期：2025-02-28 01:57:02+00:00
• 作者：Victor Mendoza-Estrada, Rafael González-Hernández, Bernardo Uribe, Libor Šmejkal
• 分类：cond-mat.mtrl-sci, math.AT
• 原文链接：http://arxiv.org/abs/2502.20646v1

原文摘要：We study the electronic, magnetic, and spin transport properties of the orthorhombic Mn$_{5}$Si$_{3}$ compound in the $AF2$ phase using symmetry analysis and ab-initio calculations. Our ground state energy calculations align with experimental observations, demonstrating that the collinear antiferromagnetic (AFM) order, with N\'{e}el vector in the [010] direction, is the most stable magnetic configuration both with and without spin-orbit coupling (SOC) in a bulk lattice geometry. We identified an unconventional eight-fold degenerate Dirac nodal line (DNL) close to the Fermi level, characterized by negligible SOC. This DNL is robustly protected by a unique combination of a pure-spin symmetry and a lattice symmetry together with magnetic space group symmetries. Upon introducing SOC, this degeneracy is reduced to two four-fold DNLs, being protected by the combination of time-reversal, partial translation and nonsymmorphic symmetries within the magnetic space group. We predict also a large intrinsic spin Hall conductivity (SHC) which correlates with the presence of SOC-induced splitting of these eight-fold degenerate DNLs near the Fermi level. These intriguing characteristics position collinear antiferromagnet Mn$_{5}$Si$_{3}$ as a compelling candidate for spintronic applications, particularly in the generation and detection of spin currents, while remaining compatible with modern silicon technology. 中文摘要：我们通过对称性分析和从头计算研究了正交晶系[[Mn$_{5}$Si$_{3}$]]化合物在$AF2$相中的电子、磁性和自旋输运性质。我们的基态能量计算与实验观察一致，表明在体晶格几何中，具有[010]方向Néel矢量的共线反铁磁（AFM）序在有无自旋轨道耦合（SOC）的情况下都是最稳定的磁构型。我们发现了一个接近费米能级的非常规八重简并狄拉克节线（DNL），其特征是SOC可忽略不计。该DNL由纯自旋对称性和晶格对称性以及磁空间群对称性的独特组合稳健保护。在引入SOC后，这种简并被减少为两个四重DNL，由磁空间群中的时间反演、部分平移和非对称性对称性的组合保护。我们还预测了一个大的本征自旋霍尔电导率（SHC），这与费米能级附近SOC诱导的八重简并DNL分裂的存在相关。这些引人注目的特性使共线反铁磁体[[Mn$_{5}$Si$_{3}$]]成为自旋电子应用的有力候选者，特别是在自旋电流的生成和检测方面，同时与现代硅技术兼容。