Study the motion of domain wall in bilayer and trilayer graphene

Layer-stacking domain walls in graphene strongly alters its electronic properties and gives rise to fascinating new physics. In bilayer graphene, domain walls between AB- and BA-stacking feature quantum valley Hall edge states, which promised novel approach to control valley degree for valleytronic devices; in trilayer graphene, they are connections of in-plane heterojunctions consisting of metallic ABA-stacking and semiconducting ABC-stacking. Domain walls take the form of soliton and can move freely in crystal. Near-field infrared nanoscopy is a powerful tool for visualizing domain walls in bilayer and trilayer graphene. In this study, we use near-field nano-imaging technique to investigate the motion of domain walls in bilayer and trilayer graphene.