Coupled topological flat and wide bands: Quasiparticle formation and destruction

Abstract

Flat bands amplify correlation effects and are of extensive current interest. They provide a platform to explore both topology in correlated settings and correlation physics enriched by topology. Recent experiments in correlated kagome metals have found evidence for strange-metal behavior. A major theoretical challenge is to study the effect of local Coulomb repulsion when the band topology obstructs a real-space description. In a variant to the kagome lattice, we identify an orbital-selective Mott transition for the first time in any system of coupled topological flat and wide bands. This was made possible by the construction of exponentially localized and Kramers-doublet Wannier functions, which in turn leads to an effective Kondo lattice description. Our findings show how quasiparticles are formed in such coupled topological flat-wide band systems and, equally important, how they are destroyed. Our work provides a conceptual framework for the understanding of the existing and emerging strange-metal properties in kagome metals and beyond.

30 pages, 6 figures. To appear in Science Advances

References in corpus (21)

• Discovery of unconventional chiral charge order in kagome superconductor KV3Sb5
• Quantum criticality
• Weak magnetism and non-Fermi liquids near heavy-fermion critical points
• Time-reversal symmetry-breaking charge order in a kagome superconductor
• Hidden Magnetism and Quantum Criticality in the Heavy Fermion Superconductor CeRhIn5
• Discovery of charge density wave in a correlated kagome lattice antiferromagnet
• MATBG as Topological Heavy Fermion: I. Exact Mapping and Correlated Insulators
• Quantum phases driven by strong correlations
• Bose condensation in flat bands
• Quantum critical behavior in magic-angle twisted bilayer graphene
• Gate-tunable heavy fermions in a moiré Kondo lattice
• Discovery of charge order and corresponding edge state in kagome magnet FeGe
• Emulating heavy fermions in twisted trilayer graphene
• Theory of High T${}_c$ Ferrimagnetism in a Multi-orbital Mott Insulator
• Exact many-electron ground states on the diamond Hubbard chain
• Non-Thermal Emergence of an Orbital-Selective Mott Phase in FeTe${}_{1-x}$Se${}_x$
• Chiral Kondo Lattice in Doped MoTe${}_2$/WSe${}_2$ Bilayers
• Correlation-Driven Electronic Reconstruction in FeTe${}_{1-x}$Se${}_x$
• Gate-tunable heavy fermion quantum criticality in a moiré Kondo lattice
• A bird's eye view on the flat and conic band world of the honeycomb and Kagome lattices: Towards an understanding of 2D Metal-Organic Frameworks electronic structure
• Construction of interacting flat-band models by molecular-orbital representation: Correlation functions, energy gap, and entanglement

Cited by in corpus (20)

• Flat bands, strange metals, and the Kondo effect
• Non-Fermi liquid behavior in a correlated flatband pyrochlore lattice
• Symmetric Kondo Lattice States in Doped Strained Twisted Bilayer Graphene
• Emergent flat band and topological Kondo semimetal driven by orbital-selective correlations
• Emergence of flat bands and ferromagnetic fluctuations via orbital-selective electron correlations in Mn-based kagome metal
• Symmetry constraints and spectral crossing in a Mott insulator with Green's function zeros
• Superconductivity in twisted WSe${}_2$ from topology-induced quantum fluctuations
• Spin Excitations and Flat Electronic Bands in a Cr-based Kagome Superconductor
• Kondo effect and its destruction in hetero-bilayer transition metal dichalcogenides
• Persistent flat band splitting and strong selective band renormalization in a kagome magnet thin film
• Quantum critical metals and loss of quasiparticles
• Electron correlations in the kagome flat band metal $\mathrm{CsC}{\mathrm{r}}_3\mathrm{S}{\mathrm{b}}_5$
• Quantum Criticality Enabled by Intertwined Degrees of Freedom
• Topological Kondo semimetals emulated in hetero-bilayer transition metal dichalcogenides
• Topological phase diagram of the Haldane model on a Bishamon-kikko--honeycomb lattice
• Topological Majorana flat bands in the Kitaev model on a Bishamon-kikko lattice
• Dichotomy of flat bands in the van der Waals ferromagnet Fe${}_5$GeTe${}_2$
• Selective Kondo screening and strange metallicity by sliding Dirac semimetals
• Reduced Wannier representation for topological bands
• Topological transition induced by selective random defects on a honeycomb lattice