Understanding the Electronic Structure of Kagome metals AV₃Sb₅ (A=K, Cs, Rb)

Nonmagnetic Kagome metals AV₃Sb₅ (A=K, Cs, Rb) have become a fascinating platform due to the observation of many novel quantum electronic states. While the DFT band structure of AV₃Sb₅ broadly agrees with Angular Resolved Photoemission Spectroscopy (ARPES), a comprehensive understanding of the electronic structure and how to construct effective models for studying exotic electron behaviors are still lacking. The properties of the low-energy DFT band structure cannot be captured by the commonly used effective Kagome tight-binding models. We address these fundamental discrepancies and developed an extended Slater-Koster tight-binding model which can successfully resolve these issues. This method can be applied to other transition-metal systems.