Kagome metals with charge density wave (CDW) order exhibit a broad spectrum
of intriguing quantum phenomena. The recent discovery of the novel kagome CDW
compound ScV6βSn6β has spurred significant interest. However, understanding
the interplay between CDW and the bulk electronic structure has been obscured
by a profusion of surface states and terminations in this quantum material.
Here, we employ photoemission spectroscopy and potassium dosing to elucidate
the complete bulk band structure of ScV6βSn6β, revealing multiple van Hove
singularities near the Fermi level. We surprisingly discover a robust
spin-polarized topological Dirac surface resonance state at the M point within
the two-fold van Hove singularities. Assisted by the first-principle
calculations, the temperature dependence of the kzβ- resolved ARPES spectrum
provides unequivocal evidence for the proposed
3βΓ3βΓ3 charge order over other candidates. Our
work not only enhances the understanding of the CDW-dependent bulk and surface
states in ScV6βSn6β but also establishes an essential foundation for
potential manipulation of the CDW order in kagome materials.Comment: To appear in PR