Polarity-dependent charge-density wave in a kagome superconductor CsV3Sb5

Abstract

Polar surface and interface play a pivotal role for realizing exotic properties of materials, and a search for such polar states is of crucial importance for expanding materials' functionality. Here we report micro-focused angle-resolved photoemission spectroscopy of CsV3Sb5, a member of recently discovered kagome superconductors AV3Sb5 (A = K, Rb, Cs), and show evidence for the polar nature of cleaved surface which is characterized by Cs- and Sb-terminated surfaces with markedly different fermiology. The Cs-terminated surface shows intriguing doubling of V-derived bands at low temperature associated with the band folding due to the three-dimensional charge-density wave (CDW), whereas the Sb-terminated one shows no band doubling or resultant CDW-gap opening indicative of the suppression of bulk-originated CDW due to polar charge. Such polar-surface-dependent band structure must be incorporated for understanding the origin of unconventional superconducting and charge order at the surface of AV3Sb5.

10 pages, 13 figures

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• Carrier Injection and Manipulation of Charge-Density Wave in Kagome Superconductor CsV3Sb5
• Observation of an electron band above the Fermi level in FeTe${}_{0.55}$Se${}_{0.45}$ from \emph{in-situ} surface doping

Cited by in corpus (8)

• Correlated Electronic Structure and Incipient Flat Bands of the Kagome Superconductor CsCr3Sb5
• Spin Excitations and Flat Electronic Bands in a Cr-based Kagome Superconductor
• Kagome metals
• Surface region band enhancement in noble gas adsorption assisted ARPES on kagome superconductor RbV3Sb5
• Evidence for reduced periodic lattice distortion within the Sb-terminated surface layer of the kagome metal CsV${}_3$Sb${}_5$
• Photoemission Insights to Electronic Orders in Kagome Superconductor AV3Sb5
• Duality and degeneracy lifting in two-dimensional electron liquids on SrTiO${}_3$(001)
• Electronic inhomogeneity in Cs- and Sb-terminated surfaces of CsV${}_3$Sb${}_5$ probed by scanning photoemission spectromicroscopy