Nature of unconventional pairing and competing Fermi surface instabilities in Kagome metals

ORAL

Abstract

Multi-pocket Fermiologies are nearly inevitable for a large range of unconventional superconductors with multi-orbital and multi-sublattice structure. The Kagome three-sublattice structure of corner sharing triangles, even in a most simplistic single orbital abstraction, already gives rise to an intricate composition of Fermi level eigenstates. As a consequence, the distinct van Hove points of a Kagome band structure experience radically different sublattice occupation. Invoking that the dominant fluctuations are determined by the coupling between the van Hove points, a local Hubbard interaction term is unable to couple them due to mismatched sublattice weight, an effect we call sublattice interference. In this talk, we will show how the suppression of this usually most dominant interaction scale allows subleading effects like nearest-neighbour interactions to dictate the pairing tendencies of the system and analyse the resulting exotic states of matter.

*The work is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) through Project-ID 258499086 - SFB 1170 and through the Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter – ct.qmat Project-ID 390858490 - EXC 2147.

Publication: M. Dürrnagel et al., Unconventional superconductivity from weak coupling. Eur. Phys. J. B 95, 112 (2022).
X. Wu et al. Nature of Unconventional Pairing in the Kagome Superconductors AV3Sb5 (A=K,Rb,Cs). Phys. Rev. Lett. 127, 177001

Presenters

  • Matteo Dürrnagel

    • Julius-Maximilians University of Wuerzburg

Authors

  • Matteo Dürrnagel

    • Julius-Maximilians University of Wuerzburg
  • Tilman Schwemmer

    • Julius-Maximilians-Universität Würzburg
    • Julius-Maximilians University of Wuerzburg
  • Hendrik Hohmann

    • Julius-Maximilians University of Wuerzburg
  • Domenico Di Sante

    • University of Bologna
  • Xianxin Wu

    • Institute of Theoretical Physics,Chinese Academy of Sciences
    • Institute of theoretical physics, Chinese Academy of Sciences
    • Max Planck Institute for Solid State Phy
  • Werner R Hanke

    • Julius-Maximilians University of Wuerzburg
  • Ronny Thomale

    • Julius-Maximilians University of Wuerzburg
    • Julius-Maximilians University of Wuerzbu
    • Institut für Theoretische Physik und Astrophysik Universität Würzburg, 97074 Würzburg, Germany
    • University of Wuerzburg