Kekulé Moiré Superlattices

Abstract

In this paper, we discuss a new moirésystem where the long moiréperiodicity emerges from two dissimilar van der Waals layers with vastly different lattice constants. We reconstruct the first layer using a 3 by 3 supercell resembling the Kekuled istortion in graphene, and such reconstruction becomes nearly commensurate with the second layer. We term this construction a Kekulémoirésuperlattice, which enables coupling between moireb ands from remote valleys in momentum space. Kekulémoireś uperlattices can be realized in heterostructures of transition metal dichalcogenides and metal phosphorus trichalcogenides such as MoTe 2 /MnPSe 3 . By first-principles calculations, we demonstrate that the antiferromagnetic MnPSe 3 strongly couples the otherwise degenerate Kramers' valleys of MoTe 2 , resulting in valley pseudospin textures that depend on the Neél vector direction, stacking geometry, and external fields. With one hole per moireś upercell, the system becomes a Chern insulator with highly tunable topological phases.