Spin and anomalous Hall effects emerging from topological degeneracy in the Dirac fermion system CuMnAs
Spin and anomalous Hall effects emerging from topological degeneracy in the Dirac fermion system CuMnAs
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狄拉克费米子系统 CuMnAs 中拓扑简并性产生的自旋和反常霍尔效应
DOI：
10.1103/physrevb.104.035110
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发表时间：
2021
影响因子：
3.7
通讯作者：
Suzuki Michi-To
中科院分区：
文献类型：
--
作者：
Huyen Vu Thi Ngoc;Yanagi Yuki;Suzuki Michi-To
正交相CuMnAs被认为是费米能级附近的反铁磁半金属结线和狄拉克点。我们研究了拓扑带和输运现象之间的关系，即，自旋霍尔效应和异常霍尔效应，在正交CuMnAs与第一性原理计算相结合的磁结构和（自旋）Berry曲率的对称性分析。我们发现，在CuMnAs的自旋轨道耦合带隙的节线主要产生大的自旋霍尔电导率在基态。尽管CuMnAs基态的磁对称性禁止了有限的反常霍尔效应，但外加磁场产生了显著的反常霍尔电导分量，并伴随着磁对称性破缺。我们确定，占主导地位的贡献，异常霍尔组件来自进一步提升的带简并下的外部磁场的分裂的节线附近的费米能量的自旋轨道耦合产生的布洛赫状态。
Orthorhombic CuMnAs has been proposed as an antiferromagnetic semimetal hosting nodal line and Dirac points around the Fermi level. We investigate relations between the topological bands and transport phenomena, i.e., the spin Hall effect and anomalous Hall effect, in orthorhombic CuMnAs with first-principles calculations combined with a symmetry analysis of the magnetic structures and of the (spin) Berry curvature. We show the nodal line gapped with spin-orbit coupling in CuMnAs dominantly generates large spin Hall conductivity in the ground state. Although the magnetic symmetry in the ground state of CuMnAs forbids the finite anomalous Hall effect, applied magnetic fields produce a significant anomalous component of the Hall conductivity with the magnetic symmetry breaking. We identify that the dominant contribution to anomalous Hall components comes from the further lifting of band degeneracy under external magnetic fields for the Bloch states generated with the splitting of nodal lines by spin-orbit coupling near the Fermi energy.