Anomalous Hall effect in antiferromagnetic perovskites
Anomalous Hall effect in antiferromagnetic perovskites
复制标题
DOI：
10.1103/physrevb.106.195149
复制
发表时间：
2022-08
影响因子：
3.7
通讯作者：
M. Naka;Y. Motome;H. Seo
中科院分区：
文献类型：
--
作者：
M. Naka;Y. Motome;H. Seo
从理论上研究了反铁磁(AFM)有序钙钛矿中的反常霍尔效应(AHE)。在Hartree-Fock近似下研究了钙钛矿型过渡金属氧化物中d$电子的多轨道Hubbard模型，利用线性响应理论研究了原子自旋-轨道耦合引起的本征AHE行为。我们考虑了轨道中存在两个($d^2$)和三个($d^3$)电子的情况，表明原子力显微镜有序态可以表现出AHE。在d^2‘情况下，$C$型AFM态在金属中产生DC AHE，在伴随轨道有序的绝缘体中产生光学(有限-欧米伽)AHE，而在$d^3’情况下，$G$型AFM绝缘态支持光学AHE。通过解析与空间群对称性相容的自旋图样中的分量，我们指定共线AFM分量负责AHE，而不是小的铁磁分量。我们讨论了AHE的微观起源：共线AFM自旋结构从晶格的三角形单元产生非零Berry相，由GdFeO$3类型的扭曲引起的复轨道混合项激活，并导致微观洛伦兹力。
We theoretically study the anomalous Hall effect (AHE) in perovskites with antiferromagnetic (AFM) orderings. By studying the multiorbital Hubbard model for $d$ electrons in perovskite transition metal oxides under the GdFeO$_3$-type distortion within the Hartree-Fock approximation, we investigate the behavior of intrinsic AHE owing to the atomic spin-orbit coupling via the linear response theory. We consider the cases where there exist two ($d^2$) and three ($d^3$) electrons in the $t_{2g}$ orbitals, and show that AFM ordered states can exhibit AHE. In the $d^2$ case, $C$-type AFM states give rise to dc AHE in metals and optical (finite-$\omega$) AHE in insulators accompanying orbital ordering, while in the $d^3$ case, a $G$-type AFM insulating state supports the optical AHE. By resolving the components in the spin patterns compatible with the space group symmetry, we specify the collinear AFM component to be responsible for the AHE, rather than the small ferromagnetic component. We discuss the microscopic origin of the AHE: the collinear AFM spin structure produces a nonzero Berry phase from the triangular units of the lattice, activated by the complex orbital mixing terms owing to the GdFeO$_3$-type distortion, and results in the microscopic Lorentz force.