Plethora of tunable Weyl fermions in kagome magnet Fe3Sn2 thin films
Plethora of tunable Weyl fermions in kagome magnet Fe3Sn2 thin films
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DOI：
10.1038/s41535-022-00521-y
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发表时间：
2022-02
影响因子：
5.7
通讯作者：
Zheng Ren;Hong Li;Shailja Sharma;Dipak Bhattarai;He Zhao;B. Rachmilowitz;F. Bahrami;F. Tafti-F.-Taf
中科院分区：
文献类型：
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作者：
Zheng Ren;Hong Li;Shailja Sharma;Dipak Bhattarai;He Zhao;B. Rachmilowitz;F. Bahrami;F. Tafti-F.-Taf
非常规磁体中磁性和电子能带拓扑的相互作用使得能够产生和精细控制新颖的电子现象。在这项工作中，我们使用扫描隧道显微镜和光谱研究薄膜的原型可果美磁铁Fe3Sn2。我们的实验揭示了一个不寻常的大量密集间隔的光谱特征跨越费米能级。这与理论预测的低能外尔费米子和相关拓扑费米弧表面态的特征是一致的。通过测量它们的响应作为磁场的函数，我们发现了与磁化方向相关的能量的显著演变。电子散射和干涉成像进一步证明了相关电子状态子集的可调性质。我们的实验提供了一个直接的可视化如何在原位自旋重取向驱动的Weyl费米子带结构的电子态密度的变化。结合以前的大量狄拉克费米子，平带和电子向列性的报告，我们的工作建立Fe3Sn2作为一个有趣的平台，窝藏一个非常广泛的拓扑和相关的电子现象。
Interplay of magnetism and electronic band topology in unconventional magnets enables the creation and fine control of novel electronic phenomena. In this work, we use scanning tunneling microscopy and spectroscopy to study thin films of a prototypical kagome magnet Fe3Sn2. Our experiments reveal an unusually large number of densely-spaced spectroscopic features straddling the Fermi level. These are consistent with signatures of low-energy Weyl fermions and associated topological Fermi arc surface states predicted by theory. By measuring their response as a function of magnetic field, we discover a pronounced evolution in energy tied to the magnetization direction. Electron scattering and interference imaging further demonstrates the tunable nature of a subset of related electronic states. Our experiments provide a direct visualization of how in-situ spin reorientation drives changes in the electronic density of states of the Weyl fermion band structure. Combined with previous reports of massive Dirac fermions, flat bands, and electronic nematicity, our work establishes Fe3Sn2as an interesting platform that harbors an extraordinarily wide array of topological and correlated electron phenomena.