Topological magnons and domain walls in twisted bilayer MoTe${}_2$

Abstract

We theoretically investigate the magnetic excitations in the quantum anomalous Hall insulator phase of twisted bilayer MoTe${}_2$ at a hole filling factor of $\nu =1$, focusing on magnon and domain wall excitations. Using a generalized interacting Kane-Mele model, we obtain the quantum anomalous Hall insualtor ground state with spin polarization. The magnon spectrum is then computed via the Bethe-Salpeter equation, revealing two low-energy topological magnon bands with opposite Chern numbers. To further explore the magnon topology, we construct a tight-binding model for the magnon bands, which is analogous to the Haldane model. We also calculate the energy cost of domain walls that separate regions with opposite Chern numbers and bind chiral edge states. Finally, we propose an effective spin model that describes both magnon and domain wall excitations, incorporating Heisenberg spin interactions and Dzyaloshinskii-Moriya interactions. The coupling constants in this model are determined from the numerical results for magnons and domain walls. This model accounts for the Ising anisotropy of the system, captures the magnon topology, and allows for the estimation of the magnetic ordering temperature. Our findings provide a comprehensive analysis of magnetic excitations in twisted MoTe${}_2$ and offer new insights into collective excitations in moiré systems.

arXiv comment15 pages,6 figures

References in corpus (69)

• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• Quantum Spin Hall Effect in Graphene
• $Z_2$ Topological Order and the Quantum Spin Hall Effect
• Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
• Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
• Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
• Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene
• Magnetic-field-induced quantized anomalous Hall effect in intrinsic magnetic topological insulator MnBi${}_2$Te${}_4$
• Intrinsic quantized anomalous Hall effect in a moiré heterostructure
• Robust axion insulator and Chern insulator phases in a two-dimensional antiferromagnetic topological insulator
• Topological insulators in twisted transition metal dichalcogenide homobilayers
• Tunable Correlated Chern Insulator and Ferromagnetism in Trilayer Graphene/Boron Nitride Moiré Superlattice
• Signatures of Fractional Quantum Anomalous Hall States in Twisted MoTe2 Bilayer
• Observation of Fractionally Quantized Anomalous Hall Effect
• Spontaneous Inter-layer Coherence in Double-Layer Quantum-Hall Systems I: Charged Vortices and Kosterlitz-Thouless Phase Transitions
• Quantum anomalous Hall effect from intertwined moiré bands
• Integer and fractional Chern insulators in twisted bilayer MoTe2
• Colloquium: Quantum anomalous Hall effect
• Observation of integer and fractional quantum anomalous Hall effects in twisted bilayer MoTe2
• A mechanism for anomalous Hall ferromagnetism in twisted bilayer graphene
• Exciton band structure of monolayer MoS2
• Electrical switching of magnetic order in an orbital Chern insulator
• Ground State and Hidden Symmetry of Magic Angle Graphene at Even Integer Filling
• A first theoretical realization of honeycomb topological magnon insulator
• A Realization of the Haldane-Kane-Mele Model in a System of Localized Spins
• Imaging orbital ferromagnetism in a moiré Chern insulator
• $\Gamma$-Valley Transition-Metal-Dichalcogenide Moirè Bands
• Charged Skyrmions and Topological Origin of Superconductivity in Magic Angle Graphene
• Fractional Chern Insulator in Twisted Bilayer MoTe${}_2$
• Fractional quantum anomalous Hall states in twisted bilayer MoTe${}_2$ and WSe${}_2$
• Competing zero-field Chern insulators in Superconducting Twisted Bilayer Graphene
• Twisted Bilayer Graphene V: Exact Analytic Many-Body Excitations in Twisted Bilayer Graphene Coulomb Hamiltonians: Charge Gap, Goldstone Modes and Absence of Cooper Pairing
• Collective Excitations of Quantum Anomalous Hall Ferromagnets in Twisted Bilayer Graphene
• Programming Correlated Magnetic States via Gate Controlled Moiré Geometry
• Imaging Chern mosaic and Berry-curvature magnetism in magic-angle graphene
• Giant magnetic field from moiré induced Berry phase in homobilayer semiconductors
• Composite Fermi Liquid at Zero Magnetic Field in Twisted MoTe${}_2$
• Magic Angles and Fractional Chern Insulators in Twisted Homobilayer TMDs
• Mapping twist-tuned multiband topology in bilayer WSe${}_2$
• Zero-field composite Fermi liquid in twisted semiconductor bilayers
• Maximally Localized Wannier Orbitals, Interaction Models and Fractional Quantum Anomalous Hall Effect in Twisted Bilayer MoTe2
• Kondo Lattice Model of Magic-Angle Twisted-Bilayer Graphene: Hund's Rule, Local-Moment Fluctuations, and Low-Energy Effective Theory
• Exciton band topology in spontaneous quantum anomalous Hall insulators: applications to twisted bilayer graphene
• Local probe of bulk and edge states in a fractional Chern insulator
• Interaction-driven topological phase diagram of twisted bilayer MoTe${}_2$
• Band mixing in the quantum anomalous Hall regime of twisted semiconductor bilayers
• Interplay between topology and correlations in the second moiré band of twisted bilayer MoTe2
• Phase transitions out of quantum Hall states in moiré materials
• Quantum Geometry and Stability of Moiré Flatband Ferromagnetism
• Skyrmions in twisted bilayer graphene: stability, pairing, and crystallization
• Adiabatic Approximation and Aharonov-Casher Bands in Twisted Homobilayer TMDs
• Ferromagnetism and its stability from the one-magnon spectrum in twisted bilayer graphene
• Domain wall competition in the Chern insulating regime of twisted bilayer graphene
• Intertwined fractional quantum anomalous Hall states and charge density waves
• Gate-tunable antiferromagnetic Chern insulator in twisted bilayer transition metal dichalcogenides
• Lattice Collective Modes from a Continuum Model of Magic-Angle Twisted Bilayer Graphene
• From electrons to baby skyrmions in Chern ferromagnets: A topological mechanism for spin-polaron formation in twisted bilayer graphene
• Theory of topological exciton insulators and condensates in flat Chern bands
• Variational Mapping of Chern Bands to Landau Levels: Application to Fractional Chern Insulators in Twisted MoTe${}_2$
• Spin skyrmion gaps as signatures of strong-coupling insulators in magic-angle twisted bilayer graphene
• Electrically tuned topology and magnetism in twisted bilayer MoTe${}_2$ at ${\nu }_h=1$
• Topological Magnons in a One-dimensional Itinerant Flatband Ferromagnet
• Trions in Twisted Bilayer Graphene
• Orbital Chern Insulator at $\nu =-2$ in Twisted MoTe${}_2$
• Excitonic topology and quantum geometry in organic semiconductors
• Quantum Geometry Probed by Chiral Excitonic Optical Response of Chern Insulators
• Interaction-induced crystalline topology of excitons
• Majorana zero modes in twisted transition metal dichalcogenides homobilayers
• Interacting phase diagram of twisted bilayer MoTe${}_2$ in magnetic field

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