Van Hove charge density waves on hexagonal lattices and kagome superconductors

I show that the charge density waves (CDWs) can realize a host of unconventional phenomena at the Van Hove singularity on the hexagonal lattices, especially in the recently uncovered kagome metals AV3Sb5 with A = K, Rb, and Cs. According to a renormalization group analysis, the imaginary CDW can develop as a leading instability and realize a chiral-flux Chern insulator. The interplay of real and imaginary CDWs further establishes a Haldane-model phase diagram, where the Chern insulator phase explains the time-reversal symmetry breaking CDW in the kagome metals AV3Sb5. Meanwhile, the real CDW can host the in-gap corner states with fractional corner charges. Finally, I discuss the onset of multidome child superconductivity in the parent CDW.

Speaker: Yu-Ping Lin

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