Topological Mixed Valence Model in Magic-Angle Twisted Bilayer Graphene

Abstract

We develop a model to describe the mixed valence regime in magic-angle twisted bilayer graphene (MATBG) using the recently developed heavy-fermion framework. By employing the large-$N$ slave-boson approach, we derive the self-consistent mean field equations and solve them numerically. We find that the SU(8) symmetry constraint moiré system exhibits novel mixed-valence properties which are different from conventional heavy-fermions systems. We find the solutions describing the physics at the filling near the Mott insulator regime in the limit of strong Coulomb interactions between the flat-band fermions. Our model can provide additional insight into the possible microscopic origin of unconventional superconductivity in MATBG.

arXiv comment4+9 pages, 3 figures

References in corpus (75)

• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
• Moire bands in twisted double-layer graphene
• Tuning superconductivity in twisted bilayer graphene
• Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene
• Graphene bilayer with a twist: electronic structure
• Magic continuum in twisted bilayer WSe2
• Origin of Magic Angles in Twisted Bilayer Graphene
• Hubbard model physics in transition metal dichalcogenide moiré bands
• Spectroscopic signatures of many-body correlations in magic angle twisted bilayer graphene
• Moiré heterostructures as a condensed matter quantum simulator
• Origin of Mott insulating behavior and superconductivity in twisted bilayer graphene
• Twistronics: Manipulating the Electronic Properties of Two-dimensional Layered Structures through their Twist Angle
• Strange metal in magic-angle graphene with near Planckian dissipation
• Theory of phonon-mediated superconductivity in twisted bilayer graphene
• Commensuration and Interlayer Coherence in Twisted Bilayer Graphene
• Electronic structure of turbostratic graphene
• Ultraflat bands and shear solitons in Moiré patterns of twisted bilayer transition metal dichalcogenides
• Cascade of electronic transitions in magic-angle twisted bilayer graphene
• Cascade of Phase Transitions and Dirac Revivals in Magic Angle Graphene
• Topological Superconductivity in Twisted Multilayer Graphene
• Twisted Bilayer Graphene: A Phonon Driven Superconductor
• Strong coupling phases of partially filled twisted bilayer graphene narrow bands
• Symmetry, maximally localized Wannier states, and low energy model for the twisted bilayer graphene narrow bands
• Magic Angle Hierarchy in Twisted Graphene Multilayers
• MATBG as Topological Heavy Fermion: I. Exact Mapping and Correlated Insulators
• Kohn-Luttinger Superconductivity in Twisted Bilayer Graphene
• The pseudo-Landau-level representation of twisted bilayer graphene: band topology and the implications on the correlated insulating phase
• Quantum valley Hall effect, orbital magnetism, and anomalous Hall effect in twisted multilayer graphene systems
• Deep moiré potentials in twisted transition metal dichalcogenide bilayers
• Entropic evidence for a Pomeranchuk effect in magic angle graphene
• Ferromagnetic Mott State in Twisted Graphene Bilayers at the Magic Angle
• Flatbands in twisted double bilayer graphene
• Band structure and topological property of twisted double bilayer graphenes
• Enhanced Valence Fluctuations Caused by f-c Coulomb Interaction in Ce-Based Heavy Electrons: Possible Origin of Pressure-Induced Enhancement of Superconducting Transition Temperature in \Ge and Related Compounds
• Tunable van Hove Singularities and Correlated States in Twisted Trilayer Graphene
• Atomic Bose-Einstein condensate in a twisted-bilayer optical lattice
• Band Symmetries and Singularities in Twisted Multilayer Graphene
• Tunable bilayer Hubbard model physics in twisted WSe2
• Multiple topological transitions in twisted bilayer graphene near the first magic angle
• Electronic band structure and pinning of Fermi energy to van Hove singularities in twisted bilayer graphene: a self consistent approach
• Emulating heavy fermions in twisted trilayer graphene
• Topological Floquet Engineering of Twisted Bilayer Graphene
• Kondo lattice model in magic-angle twisted bilayer graphene
• Heavy fermion representation for twisted bilayer graphene systems
• Correlated insulators, semimetals, and superconductivity in twisted trilayer graphene
• Kondo Lattice Model of Magic-Angle Twisted-Bilayer Graphene: Hund's Rule, Local-Moment Fluctuations, and Low-Energy Effective Theory
• Optically induced flat bands in twisted bilayer graphene
• In-plane critical magnetic fields in magic-angle twisted trilayer graphene
• Moiré and beyond in transition metal dichalcogenide twisted bilayers
• Unconventional Superconductivity in Magic-Angle Twisted Trilayer Graphene
• Heavy quasiparticles and cascades without symmetry breaking in twisted bilayer graphene
• Interactions in the 8-orbital model for twisted bilayer graphene
• Flat band carrier confinement in magic-angle twisted bilayer graphene
• Observation of Electrically Tunable van Hove Singularities in Twisted Bilayer Graphene from nanoARPES
• Symmetric Kondo Lattice States in Doped Strained Twisted Bilayer Graphene
• Floquet-Engineered Topological Flat Bands in Irradiated Twisted Bilayer Graphene
• Perfect and controllable nesting in the small angle twist bilayer graphene
• Effective Floquet Hamiltonians for periodically-driven twisted bilayer graphene
• Electronic structure calculations of twisted multi-layer graphene superlattices
• Effect of bilayer stacking on the atomic and electronic structure of twisted double bilayer graphene
• Magic-Angle Twisted Symmetric Trilayer Graphene as Topological Heavy Fermion Problem
• Floquet-engineering topological transitions in a twisted transition metal dichalcogenide homobilayer
• Kondo Phase in Twisted Bilayer Graphene -- A Unified Theory for Distinct Experiments
• TBG as Topological Heavy Fermion: II. Analytical approximations of the model parameters
• Quantum Phases of Transition Metal Dichalcogenide Moiré Systems
• Similar temperature scale for valence changes in Kondo lattices with different Kondo temperatures
• First order valence transition in YbInCu_4 in the (B,T) - plane
• Evolution from quantum anomalous Hall insulator to heavy-fermion semimetal in magic-angle twisted bilayer graphene
• Dirac Magic and Lifshitz Transitions in AA-Stacked Twisted Multilayer Graphene
• Topological heavy fermions in magnetic field
• Scaling theory of intrinsic Kondo and Hund's rule interactions in magic-angle twisted bilayer graphene
• Superconductivity in Ce-based cage compounds
• Intermediate Valence State in $\mathrm{Yb}{\mathrm{B}}_4$ Revealed by Resonant X-ray Emission Spectroscopy
• Valence transition in topological Kondo insulator

Cited by in corpus (7)

• Dynamical correlations and order in magic-angle twisted bilayer graphene
• Topological Mixed Valence Model for Twisted Bilayer Graphene
• Thermopower probing emergent local moments in magic-angle twisted bilayer graphene
• Moiré optical phonons dancing with heavy electrons in magic-angle twisted bilayer graphene
• Perturbative renormalization group approach to magic-angle twisted bilayer graphene using topological heavy fermion model
• Particle-hole Symmetric Slave Boson Method for the Mixed Valence Problem
• Antiferromagnetism and Stripe Channel Order in the $\mathrm{SU}(N)$-Symmetric Two-Channel Kondo Lattice Model