Li Peigang, Koo Jahyun, Ning Wei, Li Jinguo, Miao Leixin, Min Lujin, Zhu Yanglin, Wang Yu, Alem Nasim, Liu Chao-Xing, Mao Zhiqiang, Yan Binghai
Department of Physics and Engineering Physics, Tulane University, New Orleans, LA, 70118, USA.
Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
Nat Commun. 2020 Jul 10;11(1):3476. doi: 10.1038/s41467-020-17174-9.
Weyl semimetals exhibit unusual surface states and anomalous transport phenomena. It is hard to manipulate the band structure topology of specific Weyl materials. Topological transport phenomena usually appear at very low temperatures, which sets challenges for applications. In this work, we demonstrate the band topology modification via a weak magnetic field in a ferromagnetic Weyl semimetal candidate, CoMnAl, at room temperature. We observe a tunable, giant anomalous Hall effect (AHE) induced by the transition involving Weyl points and nodal rings. The AHE conductivity is as large as that of a 3D quantum AHE, with the Hall angle (Θ) reaching a record value ([Formula: see text]) at the room temperature among magnetic conductors. Furthermore, we propose a material recipe to generate large AHE by gaping nodal rings without requiring Weyl points. Our work reveals an intrinsically magnetic platform to explore the interplay between magnetic dynamics and topological physics for developing spintronic devices.
外尔半金属表现出异常的表面态和反常输运现象。很难操控特定外尔材料的能带结构拓扑。拓扑输运现象通常出现在非常低的温度下,这给应用带来了挑战。在这项工作中,我们展示了在室温下通过弱磁场对铁磁外尔半金属候选材料CoMnAl的能带拓扑进行修改。我们观察到由涉及外尔点和节线环的跃迁诱导的可调谐巨反常霍尔效应(AHE)。AHE电导率与三维量子AHE的电导率一样大,在室温下磁导体中的霍尔角(Θ)达到创纪录的值([公式:见原文])。此外,我们提出了一种通过打开节线环而无需外尔点来产生大AHE的材料配方。我们的工作揭示了一个本征磁性平台,用于探索磁动力学与拓扑物理之间的相互作用,以开发自旋电子器件。