We study electronic instabilities of a kagome metal with a Fermi energy close to saddle points at the hexagonal Brillouin zone face centers. Using parquet renormalization group, we determine the leading and subleading instabilities, finding superconducting, charge, orbital moment, and spin density waves. We then derive and use Landau theory to discuss how different primary density wave orders give rise to charge density wave modulations, as seen in the ${A\mathrm{V}}_3{\mathrm{Sb}}_5$ family, with $A=$ K, Rb, Cs. The results provide strong constraints on the mechanism of charge ordering and how it can be further refined from existing and future experiments.

• Received 17 April 2021
• Accepted 7 July 2021

DOI:https://doi.org/10.1103/PhysRevB.104.035142