Electron correlations and $T$-breaking density wave order in a ${\mathbb{Z}}_2$ kagome metal

Abstract

There have been extensive recent developments on kagome metals, such as T${}_m$X${}_n$ (T= Fe, Co and X= Sn, Ge) and $A$V${}_3$Sb${}_5$ ($A=$ Cs, K, Rb). An emerging issue is the nature of correlated phases when topologically \textit{non-trivial} bands cross the Fermi level. Here, we consider an extended Hubbard model on the kagome lattice in the presence of spin-orbit couplings, involving a Kramer's pair of bands that have opposite Chern numbers and are isolated in the band structure. We construct an effective model in a time-reversal (T) symmetric lattice description. We determine the correlated phases of this model and identify a density-wave order in the phase diagram. We show that this order is T-breaking, which originates from the Wannier orbitals lacking a common Wannier center -- a fingerprint of the underlying $Z_2$ topology. Implications of our results for the correlation physics of the kagome metals are discussed.

arXiv comment14 pages, 8 figures, 3 tables including Supplemental Material

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Cited by in corpus (9)

• Intrinsic nature of chiral charge order in the kagome superconductor RbV3Sb5
• Theory of the charge-density wave in $A$V${}_3$Sb${}_5$ kagome metals
• Mechanism of exotic density-wave and beyond-Migdal unconventional superconductivity in kagome metal AV3Sb5 (A=K, Rb, Cs)
• Tuning the van Hove singularities in AV${}_3$Sb${}_5$ (A = K, Rb, Cs) via pressure and doping
• Three-dimensional energy gap and origin of charge-density wave in kagome superconductor KV3Sb5
• Dynamical Study of the Origin of the Charge Density Wave in $A$V${}_3$Sb${}_5$ ($A=$K, Rb, Cs) Compounds
• Multidome superconductivity in charge density wave kagome metals
• Electronic properties of correlated kagomé metals AV${}_3$Sb${}_5$(A = K, Rb, Cs): A perspective
• Superconductivity modulated by structural phase transitions in pressurized vanadium-based kagome metals