Competing magnetic states in transition metal dichalcogenide moiré materials

Abstract

Small-twist-angle transition metal dichalcogenide (TMD) heterobilayers develop isolated flat moiré bands that are approximately described by triangular lattice generalized Hubbard models [PhysRevLett.121.026402]. In this article we explore the metallic and insulating states that appear under different control conditions at a density of one-electron per moiré period, and the transitions between them. By combining fully self-consistent Hartree-Fock theory calculations with strong-coupling expansions around the atomic limit, we identify four different magnetic states and one nonmagnetic state near the model phase diagram's metal-insulator phase-transition line. Ferromagnetic insulating states, stabilized by non-local direct exchange interactions, are surprisingly prominent.

12 pages, 7 figures

References in corpus (6)

• Flat Bands in Slightly Twisted Bilayer Graphene
• Spin liquid phase of the $S=\frac{1}{2}$ $J_1-J_2$ Heisenberg model on the triangular lattice
• Unusual ordered phases of highly frustrated magnets: a review
• Theory of a continuous Mott transition in two dimensions
• Magnetic and spin-liquid phases in the frustrated $t-t^{\prime }$ Hubbard model on the triangular lattice
• Spin-textured Chern bands in AB-stacked transition metal dichalcogenide bilayers

Cited by in corpus (16)

• Topological Phases in AB-Stacked MoTe${}_2$/WSe${}_2$: ${\mathbb{Z}}_2$ Topological Insulators, Chern Insulators, and Topological Charge Density Waves
• Frustrated magnetic interactions in a Wigner-Mott insulator
• Gate-tunable heavy fermion quantum criticality in a moiré Kondo lattice
• Intercell Moiré Exciton Complexes in Electron Lattices
• Itinerant spin polaron and metallic ferromagnetism in semiconductor moiré superlattices
• Tunable spin and valley excitations of correlated insulators in $\Gamma$-valley moiré bands
• Twistronics of Janus transition metal dichalcogenide bilayers
• Nematic excitonic insulator in transition metal dichalcogenide moiré heterobilayers
• Chiral Pseudo Spin Liquids in Moire Heterostructures
• $\text{Ab initio}$ theory of magnetism in two-dimensional $1T$-TaS${}_2$
• Mott-moiré excitons
• Interaction range and temperature dependence of symmetry breaking in strongly correlated two-dimensional moiré transition metal dichalcogenide bilayers
• Staggered Pseudo Magnetic Field in Twisted Transition Metal Dichalcogenides: Physical Origin and Experimental Consequences
• Topological multiferroic order in twisted transition metal dichalcogenide bilayers
• Layer Pseudospin Magnetism in Transition-Metal-Dichalcogenide Double-Moirés
• Light driven magnetic transitions in transition metal dichalcogenide heterobilayers