Discovery of topological Weyl fermion lines and drumhead surface states in a room temperature magnet
Discovery of topological Weyl fermion lines and drumhead surface states in a room temperature magnet
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DOI：
10.1126/science.aav2327
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发表时间：
2019-09-20
期刊：
影响因子：
56.9
通讯作者：
Hasan, M. Zahid
中科院分区：
文献类型：
--
作者：
Belopolski, Ilya;Manna, Kaustuv;Hasan, M. Zahid
由于不寻常的整体电子拓扑结构，拓扑物质表现出非常规的表面态和反常的输运。在这项研究中，我们使用光电子能谱和量子输运来阐明室温磁体Co2MnGa的拓扑结构。我们观察到尖锐的体相Weyl费米子线色散，这表明磁相中存在着非平凡的拓扑不变量。在磁体的表面上，我们观察到采用鼓头形式的电子波函数，使我们能够直接可视化块状边界拓扑对应的关键组件。通过考虑与观测到的拓扑Weyl费米子线相关的Berry曲率场，我们定量地解释了在该磁体中观察到的巨大反常霍尔响应。我们的实验结果表明，量子物质中强相互作用的电子和拓扑之间存在着丰富的相互作用。
Topological matter is known to exhibit unconventional surface states and anomalous transport owing to unusual bulk electronic topology. In this study, we use photoemission spectroscopy and quantum transport to elucidate the topology of the room temperature magnet Co2MnGa. We observe sharp bulk Weyl fermion line dispersions indicative of nontrivial topological invariants present in the magnetic phase. On the surface of the magnet, we observe electronic wave functions that take the form of drumheads, enabling us to directly visualize the crucial components of the bulk-boundary topological correspondence. By considering the Berry curvature field associated with the observed topological Weyl fermion lines, we quantitatively account for the giant anomalous Hall response observed in this magnet. Our experimental results suggest a rich interplay of strongly interacting electrons and topology in quantum matter.