Surface-sensitive electronic structure of kagome superconductor CsV3Sb5

We systematically study the electronic structure of a kagome superconductor CsV3Sb5 at different temperatures covering both its charge density wave state and normal state with angle-resolved photoemission spectroscopy. We observe that the V-shaped band around (sic)Gamma shows three different behaviors, referred to as alpha/alpha ', beta and gamma, mainly at different temperatures. Detailed investigations confirm that these bands are all from the same bulk Sb-p(z) origin, but they are quite sensitive to the sample surface conditions mainly modulated by temperature. Thus, the intriguing temperature dependent electronic behavior of the band near (sic)Gamma is affected by the sample surface condition, rather than intrinsic electronic behavior originating from the phase transition. Our result systematically reveals the confusing electronic structure behavior of the energy bands around (sic)Gamma, facilitating further exploration of the novel properties in this material.