Pressure-modulated Moiré superlattice reconstructions in twisted bilayer graphene

Abstract

Moiré superlattice reconstructions strongly regulate the electronic and mechanical properties of twisted bilayer graphene (TBG), yet their their atomic-scale structural transformations remain insufficiently understood computationally. Here, we use molecular dynamics simulations to study reconstruction characteristics of Moiré superlattices and their evolution under pressure. Our results corroborate previous experimental findings and reveal a strong dependence of pressure-modulated reconstructions on global twist angles (θ) and local stacking. We demonstrate that locally reconstructed twist angles exhibit distinct domain-specific responses: AA domains show significant enhancement at small θ, whereas AB domains display similar enhancement at larger θ. In contrast, SP domains exhibit the minimal angular dependence. This domain-specific behavior arises from pressure-induced changes in interlayer potential and in-plane elastic energy redistribution, which together govern stacking stability. Furthermore, pressure intensifies in-plane deformations localized in SP domains, driving a progressive transition from stripe-like strain localization to discrete soliton-like patterns with increasing θ. Conversely, pressure suppresses out-of-plane corrugations and reduces their angular dependence, particularly in AA domains. Our study uncovers TBG’s nanoscale mechanical response and provides a computational approach applicable to other van der Waals heterostructures.