Lithium ion intercalation induced dynamic evolution of moiré superlattices in graphene on SiC (0001)

Ion intercalation in moiré superlattices in van der Waals layered materials has gained significant interest recently. However, there is little knowledge of the dynamic intercalation process and resultant spatiotemporal evolution of the topological domain walls (TWDs) networks, owing to limited experimental techniques and molecular modelling. In this work, we employed density functional theory calculations and molecular dynamics simulations to understand the Li⁺ ion intercalation dynamics in bilayer graphene on SiC (0001) substrate observed in state-of-the-art in-situ low-energy electron microscope experiments. Combined with experimental results, we unravel a novel mechanism: coupled dynamics of Li⁺ ion intercalation and graphene stacking sliding, to understand the spatiotemporal evolution of TDWs upon Li⁺ intercalation in two types of moiré patterns: zebraic patterns and triangular patterns. The obtained knowledge lays grounds to understand the intercalation dynamics in other vdW materials and enables approaches to manipulate the layered vdW heterostructure systems for novel properties and applications.