Moiré flat Chern bands and correlated quantum anomalous Hall states generated by spin-orbit couplings in twisted homobilayer MoS${}_2$

Abstract

We predict that in a twisted homobilayer of transition-metal dichalcogenide MoS${}_2$, spin-orbit coupling in the conduction band states from $\pm K$ valleys can give rise to moiré flat bands with nonzero Chern numbers in each valley. The nontrivial band topology originates from a unique combination of angular twist and local mirror symmetry breaking in each individual layer, which results in unusual skyrmionic spin textures in momentum space with skyrmion number $\mathcal{S}=\pm 2$. Our Hartree-Fock analysis further suggests that density-density interactions generically drive the system at $1/2$-filling into a valley-polarized state, which realizes a correlated quantum anomalous Hall state with Chern number $\mathcal{C}=\pm 2$. Effects of displacement fields are discussed with comparison to nontrivial topology from layer-pseudospin magnetic fields.

4 + 10 pages, 4 + 3 figures

References in corpus (4)

• Graphene Bilayers with a Twist
• Twistronics: Manipulating the Electronic Properties of Two-dimensional Layered Structures through their Twist Angle
• Strongly Correlated Chern Insulators in Magic-Angle Twisted Bilayer Graphene
• High-temperature topological superconductivity in twisted double layer copper oxides

Cited by in corpus (5)

• Recent Developments in Fractional Chern Insulators
• Bridging the small and large in twisted transition metal dicalcogenide homobilayers: a tight binding model capturing orbital interference and topology across a wide range of twist angles
• Hofstadter spectrum of Chern bands in twisted transition metal dichalcogenides
• Non-Abelian topological superconductivity in maximally twisted double-layer spin-triplet valley-singlet superconductors
• Moiré plane wave expansion model for scanning tunneling microscopy simulations of incommensurate two-dimensional materials