论文标题

浆果曲率多物引起的高阶非线性异常霍尔效应

Higher-Order Nonlinear Anomalous Hall Effects Induced by Berry Curvature Multipoles

论文作者

Zhang, Cheng-Ping, Gao, Xue-Jian, Xie, Ying-Ming, Po, Hoi Chun, Law, K. T.

论文摘要

近年来,已经表明,浆果曲率单极和偶极子分别在异常的大厅效应和非线性霍尔效应中起着重要作用。在这项工作中,我们证明了浆果曲率多物(Fermi Energy的浆果曲率较高的力矩)可以诱导高阶非线性异常大厅(NLAH)效应。具体而言,垂直于电流方向的交流厅电压出现,其中频率是施加电流频率的整数倍数。重要的是,通过分析所有3D和2D磁点组的对称特性,我们注意到四极,己键,甚至更高的浆果曲率矩可能会导致某些材料中的前阶频率乘法。为了提供具体的示例,我们指出,由于浆果曲率四极杆引起的某些抗铁磁铁的三阶NLAH电压可以是某些抗铁磁体的领先霍尔电压,而四阶NLAH电压可以是由浆果弯曲曲率六角杆诱导的拓扑剂表面状态的主要响应。我们的结果是通过对称分析,有效的哈密顿量和第一原理计算来确定的。进一步提出了支持高阶NLAH效应的其他材料,包括2D抗铁磁铁和铁磁体,Weyl半含量和扭曲的双层石墨烯附近的量子异常大厅相。

In recent years, it has been shown that Berry curvature monopoles and dipoles play essential roles in the anomalous Hall effect and the nonlinear Hall effect respectively. In this work, we demonstrate that Berry curvature multipoles (the higher moments of Berry curvatures at the Fermi energy) can induce higher-order nonlinear anomalous Hall (NLAH) effect. Specifically, an AC Hall voltage perpendicular to the current direction emerges, where the frequency is an integer multiple of the frequency of the applied current. Importantly, by analyzing the symmetry properties of all the 3D and 2D magnetic point groups, we note that the quadrupole, hexapole and even higher Berry curvature moments can cause the leading-order frequency multiplication in certain materials. To provide concrete examples, we point out that the third-order NLAH voltage can be the leading-order Hall response in certain antiferromagnets due to Berry curvature quadrupoles, and the fourth-order NLAH voltage can be the leading response in the surface states of topological insulators induced by Berry curvature hexapoles. Our results are established by symmetry analysis, effective Hamiltonian and first-principles calculations. Other materials which support the higher-order NLAH effect are further proposed, including 2D antiferromagnets and ferromagnets, Weyl semimetals and twisted bilayer graphene near the quantum anomalous Hall phase.

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