Electron Beam Manipulation on the Moiré Superlattice of Bilayer WS ₂

The moiré superlattice in twisted transition metal dichalcogenides (TMDCs) offers a versatile platform for exploring electronic properties and correlated quantum phenomena. However, conventional fabrication methods using transfer and stacking techniques suffer from interfacial contamination and limited scalability. Here, we introduce an <i>in situ</i> focused electron beam irradiation approach to dynamically manipulate and characterize the moiré superlattice in bilayer 2<i>H</i>-WS₂ in TEM. We achieve real-time moiré pattern control, enabling precise twist angle adjustments (6-10°). Prolonged irradiation induces displacement of tungsten (W) and sulfur (S) atoms from the moiré superlattice, which migrate to heal vacancies in adjacent monolayers, ultimately collapsing the superlattice into a WS₂ monolayer and revealing an unexpected atomic-scale self-repair mechanism. This technique advances the study of twistronics in 2D quantum materials by providing a pathway for atomically precise engineering of moiré-driven electronic states while highlighting the potential of electron beam lithography (EBL) for the controllable fabrication of moiré devices.