Abstract
Kagome materials offer a versatile platform for exploring correlated and topological quantum states, where Van Hove singularities (VHSs) play a pivotal role in driving electronic instabilities, exhibiting distinct behaviors depending on electron filling and interaction settings. In the recently discovered kagome superconductors AV3Sb5 (A=K, Rb, Cs), unconventional charge density wave order, superconductivity, and electronic chirality emerge, yet the nature of VHSs near the Fermi level (EF) and their connection to these exotic orders remain elusive. Here, using high-resolution polarization-dependent angle-resolved photoemission spectroscopy, we uncover a universal electronic structure across AV3Sb5 that is distinct from density-functional theory predictions that show noticeable discrepancies. We identify multiple common sublattice-pure VHSs near EF, arising from strong V-d/Sb-p hybridization, which significantly promote bond-order fluctuations and likely drive the observed charge density wave order.
| Original language | English |
|---|---|
| Article number | 016401 |
| Journal | Physical Review Letters |
| Volume | 136 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 9 2026 |
| Externally published | Yes |
Funding
Y.H. acknowledges the support from the National Natural Science Foundation of China (Grant No. 12574156), the Fundamental Research Funds for the Central Universities (Grant No. 00130452020006), the start-up fund from Chongqing University (Grant No. 0013045203003), and Xiaomi Young Talents Program. S.D.W. and B.R.O. gratefully acknowledge the support via the UC Santa Barbara NSF Quantum Foundry funded via the Q-AMASE-i program under Award No. DMR-1906325. C.L. is supported by the start-up fund from Hefei National Laboratory and the RIKEN TRIP initiative (RIKEN Quantum). X.W. is supported by the National Key R&D Program of China (Grant No. 2023YFA1407300) and the National Natural Science Foundation of China (Grants No. 12574151, No. 12447103, and No. 12447101). M.S. was supported by the National Natural Science Foundation of China (Grant No. 12350710785), and the Fundamental Research Funds for the Central Universities (Grant No. 226-2024-00068). We thank Gerardina Carbone, Balasubramanian Thiagarajan, and Craig Polley of the Bloch beamline at MAX IV; Jonathan D. Denlinger of the MERLIN ARPES end station at ALS; and Emile Rienks of the 13-ARPES beamline at BESSY-II for their valuable technical assistance with the ARPES measurements. Y. H. acknowledges the support from the National Natural Science Foundation of China (Grant No. 12574156), the Fundamental Research Funds for the Central Universities (Grant No. 00130452020006), the start-up fund from Chongqing University (Grant No. 0013045203003), and Xiaomi Young Talents Program. S. D. W. and B. R. O. gratefully acknowledge the support via the UC Santa Barbara NSF Quantum Foundry funded via the Q-AMASE-i program under Award No. DMR-1906325. C. L. is supported by the start-up fund from Hefei National Laboratory and the RIKEN TRIP initiative (RIKEN Quantum). X. W. is supported by the National Key R&D Program of China (Grant No. 2023YFA1407300) and the National Natural Science Foundation of China (Grants No. 12574151, No. 12447103, and No. 12447101). M. S. was supported by the National Natural Science Foundation of China (Grant No. 12350710785), and the Fundamental Research Funds for the Central Universities (Grant No. 226-2024-00068). We thank Gerardina Carbone, Balasubramanian Thiagarajan, and Craig Polley of the Bloch beamline at MAX IV; Jonathan D. Denlinger of the MERLIN ARPES end station at ALS; and Emile Rienks of the -ARPES beamline at BESSY-II for their valuable technical assistance with the ARPES measurements.