Van Hove charge density waves on hexagonal lattices and kagome superconductors

Uncovering the Spin-Valley Order of Correlated Phases in Magic-Angle Graphene
September 19, 2022

Monday, September 19, 2022
Join us for the Physics Condensed Matter Seminar at 2:30 - 3:30 pm

Title: Van Hove charge density waves on hexagonal lattices and kagome superconductors

Abstract: 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.

[1] Y.-P. Lin and R. M. Nandkishore, Phys. Rev. B 100, 085136 (2019)
[2] Y.-P. Lin and R. M. Nandkishore, Phys. Rev. B 104, 045122 (2021)
[3] Y.-P. Lin, arXiv:2106.09717
[4] Y.-P. Lin and R. M. Nandkishore, Phys. Rev. B 106, L060507 (2022)

Bio: Yu-Ping just joined the University of California, Berkeley as a Moore Postdoctoral Fellow. Prior to joining Berkeley, he received the Ph.D. in Physics at the University of Colorado Boulder. He is interested in the novel nature of condensed matter systems involving topology/geometry, symmetry, interaction, singular density of states, and/or nonequilibrium (disorder and/or Floquet).

Website: https://sites.google.com/view/yupinglin/home

Join Zoom Meeting if not unable to attend in person:
https://berkeley.zoom.us/j/91441096077

Location: 325 Physics South
Speaker: Yu-ping Lin
Affiliation: University of California, Berkeley