Abstract

The coexistence of multiple moiré lattices in van der Waals heterostructures raises a fundamental question: how do distinct moiré patterns interact and reconstruct? Here, we investigate twisted bilayer graphene (tBG) on hexagonal boron nitride (h-BN), where tBG and graphene/h-BN moiré structures coexist, using conductive atomic force microscopy combined with continuum-model simulations. We show that reconstruction between these moiré lattices—moiré–moiré reconstruction—manifests across multiple length scales, giving rise to diverse commensurate double-moiré phases. Locally, the stacking registry between the two moiré lattices is uniquely selected by the global twist configuration (helical or alternate), mediated by rotational relaxation of the shared graphene layer. This registry, together with twist angle and strain, governs commensurate domains from C3z-symmetric to strained symmetry-modified structures. These results establish moiré–moiré reconstruction as a general framework for engineering structural and electronic order—including theoretically predicted topological flat bands below the magic angle—in multilayer moiré materials.

Abstract

The coexistence of multiple moiré lattices in van der Waals heterostructures raises a fundamental question: how do distinct moiré patterns interact and reconstruct? Here, we investigate twisted bilayer graphene (tBG) on hexagonal boron nitride (h-BN), where tBG and graphene/h-BN moiré structures coexist, using conductive atomic force microscopy combined with continuum-model simulations. We show that reconstruction between these moiré lattices—moiré–moiré reconstruction—manifests across multiple length scales, giving rise to diverse commensurate double-moiré phases. Locally, the stacking registry between the two moiré lattices is uniquely selected by the global twist configuration (helical or alternate), mediated by rotational relaxation of the shared graphene layer. This registry, together with twist angle and strain, governs commensurate domains from C3z-symmetric to strained symmetry-modified structures. These results establish moiré–moiré reconstruction as a general framework for engineering structural and electronic order—including theoretically predicted topological flat bands below the magic angle—in multilayer moiré materials.

Abstract

The coexistence of multiple moiré lattices in van der Waals heterostructures raises a fundamental question: how do distinct moiré patterns interact and reconstruct? Here, we investigate twisted bilayer graphene (tBG) on hexagonal boron nitride (h-BN), where tBG and graphene/h-BN moiré structures coexist, using conductive atomic force microscopy combined with continuum-model simulations. We show that reconstruction between these moiré lattices—moiré–moiré reconstruction—manifests across multiple length scales, giving rise to diverse commensurate double-moiré phases. Locally, the stacking registry between the two moiré lattices is uniquely selected by the global twist configuration (helical or alternate), mediated by rotational relaxation of the shared graphene layer. This registry, together with twist angle and strain, governs commensurate domains from C3z-symmetric to strained symmetry-modified structures. These results establish moiré–moiré reconstruction as a general framework for engineering structural and electronic order—including theoretically predicted topological flat bands below the magic angle—in multilayer moiré materials.

Abstract

The coexistence of multiple moiré lattices in van der Waals heterostructures raises a fundamental question: how do distinct moiré patterns interact and reconstruct? Here, we investigate twisted bilayer graphene (tBG) on hexagonal boron nitride (h-BN), where tBG and graphene/h-BN moiré structures coexist, using conductive atomic force microscopy combined with continuum-model simulations. We show that reconstruction between these moiré lattices—moiré–moiré reconstruction—manifests across multiple length scales, giving rise to diverse commensurate double-moiré phases. Locally, the stacking registry between the two moiré lattices is uniquely selected by the global twist configuration (helical or alternate), mediated by rotational relaxation of the shared graphene layer. This registry, together with twist angle and strain, governs commensurate domains from C3z-symmetric to strained symmetry-modified structures. These results establish moiré–moiré reconstruction as a general framework for engineering structural and electronic order—including theoretically predicted topological flat bands below the magic angle—in multilayer moiré materials.