A coarse-grained mechanical framework for twisted van der Waals layered materials

Abstract

The moiré superlattice, arising from the interlayer twisting of van der Waals (vdW) layered materials, dominates their in-plane and out-of-plane deformations, playing a pivotal role in determining the physical and mechanical properties of vdW layered materials. However, simulating the moiré superlattice-dependent mechanical behavior encounters spatiotemporal limitations from atomistic simulations. In this work, a general coarse-grained (CG) model is developed for twisted vdW layered materials, where moiré superlattices are represented as coarse particles with equivalent system energy. Comparative analysis with MD simulation results demonstrates that the developed CG model accurately reproduce the mechanical properties of vdW layered materials while capturing the influence of moiré superlattices on the out-of-plane deformation. Notably, the CG model significantly enhances computational efficiency, achieving orders of magnitude improvement depending on the twisted angle. This approach paves the way for large-scale computational simulation of twisted vdW layered materials and bridge the gap between atomistic simulations at nanoscale and experiments at micro/macroscale.