Van Hove singularity driven emergence of multiple flat band-like nondispersive features in kagome superconductors
Year: 2025
Type: article
Abstract: The newly discovered kagome superconductors $A{\mathrm{V}}_{3}{\mathrm{Sb}}_{5}$ ($A$ = K, Rb, and Cs) continue to bring surprises in generating unusual phenomena and physical properties, including the anomalous Hall effect, unconventional charge density wave, electronic nematicity, and time-reversal symmetry breaking. Here we report an unexpected emergence of multiple flat band-like nondispersive features in the $A{\mathrm{V}}_{3}{\mathrm{Sb}}_{5}$ superconductors. By performing high-resolution angle-resolved photoemission (ARPES) measurements, we observed four branches of nondispersive features that span over the entire momentum space. The appearance of the nondispersive features is not anticipated from the band structure calculations and cannot be accounted for by the known mechanisms of flat band generation. It is intimately related to the evolution of Van Hove singularities. Here we observe such emergence of multiple nondispersive features in solid materials. Our findings provide insights in revealing the underlying mechanism that governs the unusual behaviors in the kagome superconductors. They also provide a pathway in producing nondispersive features and set a platform to study flat band related physics.
Authors: Hailan Luo, Lin Zhao, Zhen Zhao, Haitao Yang, Yun-Peng Huang, Hongxiong Liu, Yuhao Gu, Feng Jin, Hao Chen, Taimin Miao, Chaohui Yin, Chengmin Shen, Xiaolin Ren, Bo Liang, Yingjie Shu, Yiwen Chen, Fengfeng Zhang, Feng Yang, Shenjin Zhang, Qinjun Peng, Hanqing Mao, Guodong Liu, Jiangping Hu, Youguo Shi, Zuyan Xu, Kun Jiang, Qingming Zhang, Ziqiang Wang, Hongjun Gao, X. J. Zhou
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: U.S. Department of Energy, National Natural Science Foundation of China, Chinese Academy of Sciences, Youth Innovation Promotion Association of the Chinese Academy of Sciences, K. C. Wong Education Foundation, National Key Research and Development Program of China, Youth Innovation Promotion Association, Basic Energy Sciences
Awards: G1108683695, G1153169839, DISORDER AND INTERACTION IN CORRELATED ELECTRON SYSTEMS, G1435206743, G1473463781, G1493320981, G1677970229, G178923758, G1913932332, G2175771557, G222768804, G223470751, G234472370, G2735571122, G28403681, G3012279778, G3276031618, G3552461366, G3600810763, G3709619708, G3839806281, G455349330, G4620811652, G4731179782, G4866772740, G4950625565, G4953843186, DISORDER AND INTERACTION IN QUANTUM HALL SYSTEMS, G5648016710, G8197912562, G828489505, G8601721673, G8771983098, G920057190
OpenAlex ID: W4409428792