FeGe as a building block for the kagome 1:1, 1:6:6, and 1:3:5 families: hidden d-orbital decoupling of flat band sectors, effective models and interaction Hamiltonians

Abstract

The electronic structure and interactions of kagome materials, such as the 1:1 (FeGe) and 1:6:6 (MgFe6Ge6) classes, are complicated and involve many orbitals and bands around the Fermi level. Current theoretical models treat the systems in an $s$-orbital kagome representation, unsuited and incorrect both quantitatively and qualitatively to the material realities. In this work, we lay the basis of a faithful framework of the electronic model for this large class of materials. We show that the complicated ``spaghetti" of electronic bands near the Fermi level can be decomposed into three groups of Fe d orbitals coupled to specific Ge orbitals via symmetry and chemical analysis. Such a decomposition allows for a clear analytical understanding (leading to different results than the simple s-orbital kagome models) of the flat bands in the system based on the S-matrix formalism of generalized bipartite lattices. Our three minimal Hamiltonians can reproduce the quasiflat bands, van Hove singularities, topology, and Dirac points close to the Fermi level, which we prove by extensive ab initio studies. We also obtain the interacting Hamiltonian for the d orbitals in FeGe using the constraint random phase approximation (cRPA) method, which faithfully describes the antiferromagnetic phase. We then use FeGe as a fundamental LEGO-like building block for a large family of 1:6:6 kagome materials, which can be obtained by doubling and perturbing the FeGe Hamiltonian. We apply the model to its kagome siblings FeSn and CoSn, and also MgFe6Ge6. We further extend the formalism developed for the 1:1 family to the 1:3:5 family AB3Z5 (A = K, Rb, Cs; B = Cr, V, Ti; Z = Sb, Bi), demonstrating the broad applicability of the LEGO-like building block approach. Our work serves as the first complete framework for the study of the interacting phase diagram of kagome compounds.

82 pages. This is the second paper of a series on kagome materials. See also the first paper: arXiv:2305.15469

References in corpus (108)

• CsV${}_3$Sb${}_5$: a ${\mathbb{Z}}_2$ topological kagome metal with a superconducting ground state
• Strong electronic correlations from Hund's coupling
• Discovery of unconventional chiral charge order in kagome superconductor KV3Sb5
• Roton pair density wave and unconventional strong-coupling superconductivity in a topological kagome metal
• Cascade of correlated electron states in a kagome superconductor CsV3Sb5
• Topological kagome magnets and superconductors
• Unconventional Fermi surface instabilities in the Kagome Hubbard Model
• Time-reversal symmetry-breaking charge order in a kagome superconductor
• Charge density waves and electronic properties of superconducting kagome metals
• Calculations of Hubbard U from first-principles
• Superconductivity in the ${\mathbb{Z}}_2$ kagome metal KV${}_3$Sb${}_5$
• Topological flat bands in frustrated kagome lattice CoSn
• Double superconducting dome and triple enhancement of Tc in the kagome superconductor CsV3Sb5 under high pressure
• Concurrence of anomalous Hall effect and charge density wave in a superconducting topological kagome metal
• Three-dimensional charge density wave and robust zero-bias conductance peak inside the superconducting vortex core of a kagome superconductor CsV${}_3$Sb${}_5$
• Superconductivity and normal-state properties of kagome metal RbV3Sb5 single crystals
• Unusual competition of superconductivity and charge-density-wave state in a compressed topological kagome metal
• Hubbard U and Hund's Exchange J in Transition Metal Oxides: Screening vs. Localization Trends from Constrained Random Phase Approximation
• Observation of Unconventional Charge Density Wave without Acoustic Phonon Anomaly in Kagome Superconductors AV3Sb5 (A=Rb,Cs)
• Chiral flux phase in the Kagome superconductor AV${}_3$Sb${}_5$
• Analysis of Charge Order in the Kagome Metal $A$V${}_3$Sb${}_5$ ($A=$K,Rb,Cs)
• Discovery of charge density wave in a correlated kagome lattice antiferromagnet
• Magnetic Topological Quantum Chemistry
• Building Blocks of Topological Quantum Chemistry: Elementary Band Representations
• Nature of unconventional pairing in the kagome superconductors AV${}_3$Sb${}_5$
• Electronic Nature of Charge Density Wave and Electron-Phonon Coupling in Kagome Superconductor KV${}_3$Sb${}_5$
• Rotation symmetry breaking in the normal state of a kagome superconductor KV3Sb5
• Fermi surface mapping and the nature of charge density wave order in the kagome superconductor CsV${}_3$Sb${}_5$
• Complex charge density waves at Van Hove singularity on hexagonal lattices: Haldane-model phase diagram and potential realization in kagome metals ${\text{AV}}_3{\text{Sb}}_5$
• Multiband superconductivity with sign-preserving order parameter in kagome superconductor CsV3Sb5
• Novel magnetic states and nematic spin chirality in the kagome lattice metal YMn${}_6$Sn${}_6$
• Twofold symmetry of $c$-axis resistivity in topological kagome superconductor CsV${}_3$Sb${}_5$ with in-plane rotating magnetic field
• Orbital-selective Dirac fermions and extremely flat bands in frustrated kagome-lattice metal CoSn
• Electronic nature of chiral charge order in the kagome superconductor CsV3Sb5
• Charge density wave in kagome lattice intermetallic ScV6Sn6
• Intertwined magnetism and charge density wave order in kagome FeGe
• Intrinsic nature of chiral charge order in the kagome superconductor RbV3Sb5
• Enumeration and representation theory of spin space groups
• s-wave superconductivity in kagome metal CsV${}_3$Sb${}_5$ revealed by ${}^{121/123}$Sb NQR and ${}^{51}$V NMR measurements
• Interplay between charge order and superconductivity in the kagome metal KV${}_3$Sb${}_5$
• Nodeless superconductivity in the kagome metal CsV${}_3$Sb${}_5$
• Multiple Energy Scales and Anisotropic Energy Gap in the Charge-Density-Wave Phase of Kagome Superconductor CsV3Sb5
• Spin Space Groups: Full Classification and Applications
• Absence of local moments in the kagome metal KV3Sb5 as determined by muon spin spectroscopy
• Emergence of new van Hove singularities in the charge density wave state of a topological kagome metal RbV3Sb5
• Charge-order-assisted topological surface states and flat bands in the kagome superconductor CsV${}_3$Sb${}_5$
• Anisotropic superconducting properties of Kagome metal CsV3Sb5
• Enumeration of spin-space groups: Towards a complete description of symmetries of magnetic orders
• Coherent phonon spectroscopy and interlayer modulation of charge density wave order in the kagome metal CsV${}_3$Sb${}_5$
• Charge-density-wave-induced bands renormalization and energy gaps in a kagome superconductor RbV3Sb5
• Charge density wave orders and enhanced superconductivity under pressure in the kagome metal CsV3Sb5
• Discovery of charge order and corresponding edge state in kagome magnet FeGe
• Electron-phonon coupling in the charge density wave state of CsV${}_3$Sb${}_5$
• Superconductivity emerging from density-wave-like order in a correlated kagome metal
• Charge order landscape and competition with superconductivity in kagome metals
• Optical detection of charge-density-wave instability in the non-magnetic kagome metal KV${}_3$Sb${}_5$
• Competition between charge-density-wave and superconductivity in the kagome metal RbV3Sb5
• Low-energy optical properties of the non-magnetic kagome metal CsV${}_3$Sb${}_5$
• Spin-Orbit-Induced Topological Flat Bands in Line and Split Graphs of Bipartite Lattices
• Double-dome superconductivity under pressure in the V-based Kagome metals AV3Sb5 (A = Rb and K)
• MagneticTB: A package for tight-binding model of magnetic and non-magnetic materials
• Softening of a flat phonon mode in the kagome ScV${}_6$Sn${}_6$
• Competing charge-density wave instabilities in the kagome metal ScV${}_6$Sn${}_6$
• Abundant lattice instability in kagome metal ScV${}_6$Sn${}_6$
• Spin-phonon coupling driven Charge density wave in a Kagome Magnet
• Manipulation of Jeff=3/2 states by tuning the tetragonal distortion
• Unconventional charge density wave and photoinduced lattice symmetry change in Kagome Metal CsV${}_3$Sb${}_5$ probed by time-resolved spectroscopy
• Observation of Flat Band, Dirac Nodal Lines and Topological Surface States in Kagome Superconductor CsTi${}_3$Bi${}_5$
• Correlated order at the tipping point in the kagome metal CsV${}_3$Sb${}_5$
• Structural evolution of the kagome superconductors $A$V${}_3$Sb${}_5$ ($A$ = K, Rb, and Cs) through charge density wave order
• Optical spectroscopy and band structure calculations of structural phase transition in the Vanadium-based kagome metal ScV${}_6$Sn${}_6$
• Competing superconductivity and charge-density wave in Kagome metal CsV3Sb5: evidence from their evolutions with sample thickness
• Phonon collapse and van der Waals melting of the 3D charge density wave of VSe${}_2$
• Spin excitations in metallic kagome lattice FeSn and CoSn
• Chiral properties of the zero-field spiral state and field-induced magnetic phases of the itinerant kagome metal YMn${}_6$Sn${}_6$
• Order-disorder Peierls instability in the kagome metal (Cs,Rb)V${}_3$Sb${}_5$
• Phonon promoted charge density wave in topological kagome metal ScV${}_6$Sn${}_6$
• Interaction-induced quantum anomalous Hall phase in (111) bilayer of LaCoO${}_3$
• Role of Sb in the superconducting kagome metal CsV${}_3$Sb${}_5$ revealed by its anisotropic compression
• Superconductivity and orbital-selective nematic order in a new titanium-based kagome metal CsTi3Bi5
• Strain-sensitive superconductivity in kagome metals KV${}_3$Sb${}_5$ and CsV${}_3$Sb${}_5$ probed by point-contact spectroscopy
• Enhanced Spin-polarization via Partial Ge1-dimerization as the Driving Force of the 2$\times$2$\times$2 CDW in FeGe
• Tunable van Hove singularity without structural instability in Kagome metal CsTi${}_3$Bi${}_5$
• Charge density wave order and fluctuations above T${}_{CDW}$ and below superconducting T${}_c$ in the kagome metal CsV${}_3$Sb${}_5$
• GdV6Sn6: a Multi-carrier Metal with Non-magnetic 3d-electron Kagome Bands and 4f-electron Magnetism
• Experimental evidence for Berry curvature multipoles in antiferromagnets
• Annealing-tunable charge density wave in the kagome antiferromagnet FeGe
• Nanoscale visualization and spectral fingerprints of the charge order in ScV6Sn6 distinct from other kagome metals
• Novel three-dimensional Fermi surface and electron-correlation-induced charge density wave in FeGe
• Quantum oscillations revealing topological band in kagome metal ScV6Sn6
• Symmetry invariants and classes of quasiparticles in magnetically ordered systems having weak spin-orbit coupling
• Dynamics and Resilience of the Charge Density Wave in a bilayer kagome metal
• Endless Dirac nodal lines in kagome-metal Ni3In2S2
• Magnetic interactions and possible structural distortion in kagome FeGe from first-principles study and symmetry analysis
• Competing itinerant and local spin interactions in kagome metal FeGe
• Superconducting, topological and transport properties of kagome metals CsTi${}_3$Bi${}_5$ and RbTi${}_3$Bi${}_5$
• Universal sublinear resistivity in vanadium kagome materials hosting charge density waves
• Origin and stability of the charge density wave in ScV${}_6$Sn${}_6$
• Annealing-induced long-range charge density wave order in magnetic kagome FeGe: fluctuations and disordered structure
• Symmetry breaking and ascending in the magnetic kagome metal FeGe
• Origin of $\pi$-shifted three-dimensional charge density waves in kagome metal AV${}_3$Sb${}_5$
• Visualizing the Localized Electrons of a Kagome Flat Band
• Phenomenology of bond and flux orders in kagome metals
• Kagome Materials I: SG 191, ScV${}_6$Sn${}_6$. Flat Phonon Soft Modes and Unconventional CDW Formation: Microscopic and Effective Theory
• Chemical Rules for Stacked Kagome and Honeycomb Topological Semimetals
• Instability of the charge density wave in Kagome magnet FeGe
• Enhancement of the superconductivity and quantum metallic state in the thin film of superconducting Kagome metal KV${}_3$Sb${}_5$
• Charge-density wave fluctuation driven composite order in the layered Kagome Metals

Cited by in corpus (10)

• Kagome metals
• Frustrated charge density wave and quasi-long-range bond-orientational order in the magnetic kagome FeGe
• Tunability of charge density wave in a magnetic kagome metal
• Exotic charge density waves and superconductivity on the Kagome Lattice
• Loop Current Order on the Kagome Lattice
• Chemical enhancement of superconductivity in LaRu3Si2 with mode-selective coupling between kagome phonons and flat bands
• Interplay of Charge Density Wave and Magnetism on the Kagomé Lattice
• Ferromagnetism vs. Antiferromagnetism in Narrow-Band Systems: Competition Between Quantum Geometry and Band Dispersion
• Beyond kagome: $p$-bands in kagome metals
• Role of On-site and Inter-site Coulomb Interactions in KV${}_3$Sb${}_5$: A first-principles DFT+$U$+$V$ study