Unconventional anomalous Hall effect from antiferromagnetic domain walls ofNd2Ir2O7thin films
Unconventional anomalous Hall effect from antiferromagnetic domain walls ofNd2Ir2O7thin films
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DOI：
10.1103/physrevb.98.125103
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发表时间：
2018-07
影响因子：
3.7
通讯作者：
W. Kim;J. Gruenewald;Taekoo Oh;Sangmo Cheon;Bongju Kim;O. Korneta;Hwanbeom Cho;Daesu Lee;Yoonkoo Kim;Miyoung Kim;Je-Guen Park;Bohm-Jung Yang;A. Seo;T. Noh
中科院分区：
文献类型：
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作者：
W. Kim;J. Gruenewald;Taekoo Oh;Sangmo Cheon;Bongju Kim;O. Korneta;Hwanbeom Cho;Daesu Lee;Yoonkoo Kim;Miyoung Kim;Je-Guen Park;Bohm-Jung Yang;A. Seo;T. Noh
铁电畴壁（DW）创建不同的对称性和有序状态相比，在单畴块体材料。特别是，具有非共面自旋结构的反铁磁（AFM）的DW具有明显的对称性，这在它们的铁磁对应物中是无法实现的。在本文中，我们表明，一个非常规的异常霍尔效应（AHE）可以产生从DW的非共面原子力显微镜，Nd 2 Ir 2 O 7。大块Nd 2 Ir 2 O 7具有立方对称性;因此，在没有施加磁场的情况下，其霍尔信号应该为零。在这种材料中产生的DW打破了双重旋转对称性，这允许有限的异常霍尔电导率。Nd和Ir磁矩之间的强f-d交换相互作用显着影响反铁磁畴翻转。我们的外延Nd 2 Ir 2 O 7薄膜表现出大的增强AHE信号时，AFM域切换，表明AHE主要是由于DW。我们的研究突出了原子力显微镜材料的对称破缺界面作为探索拓扑效应及其相关应用的新手段。
Ferroic domain walls (DWs) create different symmetries and ordered states compared with those in single-domain bulk materials. In particular, the DWs of an antiferromagnet (AFM) with non-coplanar spin structure have a distinct symmetry that cannot be realized in those of their ferromagnet counterparts. In this paper, we show that an unconventional anomalous Hall effect (AHE) can arise from the DWs of a non-coplanar AFM, Nd2Ir2O7. Bulk Nd2Ir2O7 has a cubic symmetry; thus, its Hall signal should be zero without an applied magnetic field. The DWs generated in this material break the two-fold rotational symmetry, which allows for finite anomalous Hall conductivity. A strong f-d exchange interaction between the Nd and Ir magnetic moments significantly influences antiferromagnetic domain switching. Our epitaxial Nd2Ir2O7 thin film showed a large enhancement of the AHE signal when the AFM domains switched, indicating that the AHE is mainly due to DWs. Our study highlights the symmetry broken interface of AFM materials as a new means of exploring topological effects and their relevant applications.