Anisotropic Surface State Band Splitting and Low Energy Flat Bands in 3d Correlated Topological Kondo Insulator Candidate FeSb₂

@misc{cao2026anisotropic,
  title = {{Anisotropic Surface State Band Splitting and Low Energy Flat Bands in 3d Correlated Topological Kondo Insulator Candidate FeSb$_2$}},
  author = {Ziling Cao and Jie Pang and Yu Xu and Taimin Miao and Bo Liang and Wenpei Zhu and Neng Cai and Mingkai Xu and Jumin Shi and Yingjie Shu and Yiwen Chen and Jiachen Wang and Shenjin Zhang and Fengfeng Zhang and Feng Yang and Zhimin Wang and Qinjun Peng and Zhihai Zhu and Xintong Li and Hanqing Mao and Guodong Liu and Zuyan Xu and Youguo Shi and Lin Zhao and X. J. Zhou},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.24854},
  eprint = {2609.24854},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.24854},
}

TY  - UNPB
TI  - Anisotropic Surface State Band Splitting and Low Energy Flat Bands in 3d Correlated Topological Kondo Insulator Candidate FeSb_2
AU  - Ziling Cao
AU  - Jie Pang
AU  - Yu Xu
AU  - Taimin Miao
AU  - Bo Liang
AU  - Wenpei Zhu
AU  - Neng Cai
AU  - Mingkai Xu
AU  - Jumin Shi
AU  - Yingjie Shu
AU  - Yiwen Chen
AU  - Jiachen Wang
AU  - Shenjin Zhang
AU  - Fengfeng Zhang
AU  - Feng Yang
AU  - Zhimin Wang
AU  - Qinjun Peng
AU  - Zhihai Zhu
AU  - Xintong Li
AU  - Hanqing Mao
AU  - Guodong Liu
AU  - Zuyan Xu
AU  - Youguo Shi
AU  - Lin Zhao
AU  - X. J. Zhou
PY  - 2026
DA  - 2026/09/21
PB  - arXiv
DO  - 10.48550/arxiv.2609.24854
UR  - https://arxiv.org/abs/2609.24854
AB  - 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 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 ∼127 meV below the Fermi level, which exists only along a specific high-symmetry direction, while the other is located at ∼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.
ER  -