English

Electron correlations in kagome metals $AV_3Sb_5$ (A= K, Rb, Cs)

Strongly Correlated Electrons 2025-10-08 v2 Superconductivity

Abstract

The investigation of electronic order-quantum phase interplay in kagome lattices commonly employs the extended Kagome-Hubbard model, where the critical parameters comprise on-site (U)(U) and intersite (V)(V) Coulomb interactions. In prototypical kagome metals \ch{AV3Sb5} (A = K, Rb, Cs), the geometrically frustrated quasi-2D architecture induces pressure-dependent complexity in vanadium d-electron correlations, necessitating systematic theoretical scrutiny. Utilizing the ddpd-dp model within constrained random phase approximation (cRPA), we quantified UU, VV, and Hund's coupling JJ under hydrostatic pressure (0-9 GPa). While \ch{KV3Sb5} and \ch{RbV3Sb5} exhibit pressure-insensitive interaction parameters, \ch{CsV3Sb5} manifests anomalous discontinuities in UU and VV near 0.20.2 GPa, suggesting a first-order electronic phase transition. This work establishes cRPA-derived interaction landscapes as critical predictors for pressure-tunable quantum phenomena in correlated kagome systems, offers a new insight into the understanding of the interplay between the CDW transition and the double superconductivity dome in \ch{CsV3Sb5} at low pressure.

Keywords

Cite

@article{arxiv.2506.09864,
  title  = {Electron correlations in kagome metals $AV_3Sb_5$ (A= K, Rb, Cs)},
  author = {Feihu Liu and Changxu Liu and Maolin Zeng and Qiyi Zhao},
  journal= {arXiv preprint arXiv:2506.09864},
  year   = {2025}
}

Comments

Revised version, 11 pages, 10 figures