WikiEdge:ArXiv速遞/2025-02-28

摘要

• 原文標題：Eightfold Degenerate Dirac Nodal Line in Collinear Antiferromagnet Mn$_5$Si$_3$
• 中文標題：共線反鐵磁體Mn$_5$Si$_3$中的八重簡併狄拉克節線
• 發佈日期：2025-02-28 01:57:02+00:00
• 作者：Victor Mendoza-Estrada, Rafael González-Hernández, Bernardo Uribe, Libor Šmejkal
• 分類：cond-mat.mtrl-sci, math.AT
• 原文連結：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：我們通過對稱性分析和從頭計算研究了正交晶系[[Mn$_{5}$Si$_{3}$]]化合物在$AF2$相中的電子、磁性和自旋輸運性質。我們的基態能量計算與實驗觀察一致，表明在體晶格幾何中，具有[010]方向Néel矢量的共線反鐵磁（AFM）序在有無自旋軌道耦合（SOC）的情況下都是最穩定的磁構型。我們發現了一個接近費米能級的非常規八重簡併狄拉克節線（DNL），其特徵是SOC可忽略不計。該DNL由純自旋對稱性和晶格對稱性以及磁空間群對稱性的獨特組合穩健保護。在引入SOC後，這種簡併被減少為兩個四重DNL，由磁空間群中的時間反演、部分平移和非對稱性對稱性的組合保護。我們還預測了一個大的本徵自旋霍爾電導率（SHC），這與費米能級附近SOC誘導的八重簡併DNL分裂的存在相關。這些引人注目的特性使共線反鐵磁體[[Mn$_{5}$Si$_{3}$]]成為自旋電子應用的有力候選者，特別是在自旋電流的生成和檢測方面，同時與現代矽技術兼容。