Observation of flat band, Dirac nodal lines and topological surface states in Kagome superconductor CsTi3Bi5
Abstrak
Abstract Kagome lattices of various transition metals are versatile platforms for achieving anomalous Hall effects, unconventional charge-density wave orders and quantum spin liquid phenomena due to the strong correlations, spin-orbit coupling and/or magnetic interactions involved in such a lattice. Here, we use laser-based angle-resolved photoemission spectroscopy in combination with density functional theory calculations to investigate the electronic structure of the newly discovered kagome superconductor CsTi3Bi5, which is isostructural to the AV3Sb5 (A = K, Rb or Cs) kagome superconductor family and possesses a two-dimensional kagome network of titanium. We directly observe a striking flat band derived from the local destructive interference of Bloch wave functions within the kagome lattice. In agreement with calculations, we identify type-II and type-III Dirac nodal lines and their momentum distribution in CsTi3Bi5 from the measured electronic structures. In addition, around the Brillouin zone centre, $${{\mathbb{Z}}}_{2}$$ Z 2 nontrivial topological surface states are also observed due to band inversion mediated by strong spin-orbit coupling.
Topik & Kata Kunci
Penulis (26)
Jiangang Yang
Xinwei Yi
Zhen Zhao
Yuyang Xie
Taimin Miao
Hailan Luo
Hao Chen
Bo Liang
Wenpei Zhu
Yuhan Ye
Jing-Yang You
Bo Gu
Shenjin Zhang
Fengfeng Zhang
Feng Yang
Zhimin Wang
Qinjun Peng
Hanqing Mao
Guodong Liu
Zuyan Xu
Hui Chen
Haitao Yang
Gang Su
Hongjun Gao
Lin Zhao
X. J. Zhou
Akses Cepat
- Tahun Terbit
- 2023
- Sumber Database
- DOAJ
- DOI
- 10.1038/s41467-023-39620-0
- Akses
- Open Access ✓