发表机构
National Laboratory for Superconductivity, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences; University of Chinese Academy of Sciences; Technical Institute of Physics and Chemistry, Chinese Academy of Sciences（中国科学院物理研究所; 中国科学院大学; 中国科学院理化技术研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
通过高分辨率ARPES研究FeSb$_2$，发现表面态各向异性劈裂及两个低能平带，为理解其重正化效应、电阻平台和拓扑性质提供新信息。
AI 中文摘要
FeSb$_2$是一种关联窄隙半导体，常被讨论为$3d$电子近藤绝缘体候选材料，并表现出低温电阻平台，可能具有表面主导的导电性。我们利用基于激光的高分辨率角分辨光电子能谱（ARPES）对FeSb$_2$进行了系统的研究，以探究其电子结构。中心区域周围的表面态显示出清晰各向异性的劈裂。当温度降至电阻平台区间（$<6\\,\mathrm{K}$）时，表面态保持稳健，但其光电子峰变得更加尖锐并获得了谱权重。在低能区观察到两个不同的类平带特征。一个位于费米能级以下约127 meV处，仅沿特定高对称方向存在；另一个位于费米能级以下约70 meV处，在中心区域周围所有测量的动量切割中均存在。这些结果为理解FeSb$_2$的重正化效应、电阻平台和拓扑性质提供了新信息。
英文摘要
FeSb$_2$ is a correlated narrow-gap semiconductor that has often been discussed as a $3d$-electron Kondo insulator candidate and exhibits a low-temperature resistance plateau with possible surface-dominated conduction. We carried out a systematic high-resolution laser-based angle-resolved photoemission spectroscopy (ARPES) study of FeSb$_2$ to investigate its electronic structure. The surface states around the zone center show clear anisotropic splitting. When the temperature is lowered into the resistance plateau regime ($<6\,\mathrm{K}$), the surface states remain robust, but their photoemission peaks become much sharper and gain spectral weight. Two distinct flat-band-like features are observed at low energy. One is located at $\sim$127 meV below the Fermi level, which exists only along a specific high-symmetry direction, while the other is located at $\sim$70 meV below the Fermi level and is present along all the measured momentum cuts around the zone center. These results provide new information to understand the renormalization effects, the resistance plateau, and the topological nature of FeSb$_2$.
Comments18 pages, 6 figures
Journal refChinese Physics B 35, 097901 (2026)
