Multiscale models for incommensurate layered two-dimensional materials

Abstract:

Manipulating the twist angle or lattice mismatch in stacks of multilayerd two-dimensional (2D) materials, referred to as van der Waals (vdW) heterostructures, introduces a long-wavelength moiré potential that fundamentally alters the physical properties of the constituent materials. The long length scale and lack of periodicity hinder the ability to model the properties of these complex multilayered heterostructures. In this talk, I will present an accurate and efficient multiscale framework that is based on first-principles Density Functional Theory calculations and bypasses the need for a supercell approximation. Using this framework, I study the electronic and mechanical properties of moiré of moiré vdW heterostructures such as twisted trilayer graphene with two independent twist angles. I also apply the same framework to model the low-energy moiré phonon modes in twisted bilayer heterostructures.