Flat-band ferromagnetism and spin waves in the Haldane-Hubbard model
arXiv:2106.00468 · doi:10.1103/PhysRevB.104.155129
Abstract
We study the flat-band ferromagnetic phase of the Haldane-Hubbard model on a honeycomb lattice within a bosonization scheme for flat-band Chern insulators, focusing on the calculation of the spin-wave excitation spectrum. We consider the Haldane-Hubbard model with the noninteracting lower bands in a nearly-flat band limit, previously determined for the spinless model, and at 1/4-filling of its corresponding noninteracting limit. Within the bosonization scheme, the Haldane-Hubbard model is mapped into an effective interacting boson model, whose quadratic term allows us to determine the spin-wave spectrum at the harmonic approximation. We show that the excitation spectrum has two branches with a Goldstone mode and Dirac points at center and at the K and K' points of the first Brillouin zone, respectively. We also consider the effects on the spin-wave spectrum due to an energy offset in the on-site Hubbard repulsion energies and due to the presence of an staggered on-site energy term, both quantities associated with the two triangular sublattices. In both cases, we find that an energy gap opens at the K and K' points. Moreover, we also find some evidences for an instability of the flat-band ferromagnetic phase in the presence of the staggered on-site energy term. We provide some additional results for the square lattice topological Hubbard model previous studied within the bosonization formalism and comment on the differences between the bosonization scheme implementation for the correlated Chern insulators on both square and honeycomb lattices.
arXiv comment17 pages, 11 figures, final version
References in corpus (53)
- Topological insulators and superconductors
- Magic-angle graphene superlattices: a new platform for unconventional superconductivity
- Experimental realisation of the topological Haldane model
- Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene
- Superconductors, Orbital Magnets, and Correlated States in Magic Angle Bilayer Graphene
- High temperature fractional quantum Hall states
- Fractional quantum Hall states at zero magnetic field
- Nearly-flat bands with nontrivial topology
- Topological Bands for Ultracold Atoms
- Flat Bands in Slightly Twisted Bilayer Graphene
- Topological Quantum Matter with Ultracold Gases in Optical Lattices
- Fractional quantum Hall effect in the absence of Landau levels
- Fractional Chern Insulator
- Topological Flat Band Models and Fractional Chern Insulators
- Theory of phonon-mediated superconductivity in twisted bilayer graphene
- Fractional Quantum Hall Physics in Topological Flat Bands
- Topological Superconductivity in Twisted Multilayer Graphene
- From Nagaoka's ferromagnetism to flat-band ferromagnetism and beyond: An introduction to ferromagnetism in the Hubbard model
- Interacting topological insulators: a review
- Topological Magnon Insulator in Insulating Ferromagnet
- Topological spin excitations in honeycomb ferromagnet CrI
- A first theoretical realization of honeycomb topological magnon insulator
- Correlation effects in two-dimensional topological insulators
- Ferromagnetic Mott State in Twisted Graphene Bilayers at the Magic Angle
- Ferromagnetism in narrow bands of moiré superlattices
- Topological honeycomb magnon Hall effect: A calculation of thermal Hall conductivity of magnetic spin excitations
- Two-Dimensional Density-Matrix Topological Fermionic Phases: Topological Uhlmann Numbers
- Topological phase transitions in the repulsively interacting Haldane-Hubbard model
- Interaction-stabilized topological magnon insulator in ferromagnets
- Fractional (Chern and topological) insulators
- A study on correlation effects in two dimensional topological insulators
- Realization of Topological Mott Insulator in a Twisted Bilayer Graphene Lattice Model
- Haldane-Hubbard Mott Insulator: From Tetrahedral Spin Crystal to Chiral Spin Liquid
- Fractional quantum Hall states for moiré superstructures in the Hofstadter regime
- Spontaneous quantum Hall effect in quarter-doped Hubbard model on honeycomb lattice and its possible realization in quarter-doped graphene system
- Stability of Ferromagnetism in Hubbard Models with Nearly-Flat Bands
- Chiral Spin Liquid in Correlated Topological Insulator
- First order topological phase transition of the Haldane--Hubbard model
- Magnetic Order Driven Topological Transition in the Haldane-Hubbard Model
- Topological order in a correlated Chern insulator
- Ferromagnetism and its stability from the one-magnon spectrum in twisted bilayer graphene
- Topological Hubbard model and its high-temperature quantum Hall effect
- Topological magnon bands for magnonics
- Competing Chiral Orders in the Topological Haldane-Hubbard Model of Spin-1/2 Fermions and Bosons
- Quantum cluster approach to the spinful Haldane-Hubbard model
- Abelian topological order of and fractional quantum Hall states in lattice models
- Mean field study of the topological Haldane-Hubbard model of spin- fermions
- Lowest Landau level bosonization
- Quantum Hall ferromagnetism in graphene: a SU(4) bosonization approach
- Ferromagnetism and spin excitations in topological Hubbard models with a flatband
- Flat-band ferromagnetism in a topological Hubbard model
- Hubbard models with nearly flat bands: Ground-state ferromagnetism driven by kinetic energy
- Itinerant topological magnons in Haldane Hubbard model with a nearly-flat electron band
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- Flat-band ferromagnetism in a correlated topological insulator on a honeycomb lattice
- Quantum Magnetism in Wannier-Obstructed Mott Insulators
- Magnetic fluctuations near the Van Hove singularity in the kagome-lattice Hubbard model at finite doping
- Invisible flat bands on a topological chiral edge