Fig. 1: Periodic restructuring of twisted bilayer graphene (TBG).
From: Torsional periodic lattice distortions and diffraction of twisted 2D materials
a Displacement field of torsional PLD. Local rotational fields for the AA region and AB/BA regions are opposite. By including higher harmonics, PLD can exhibit any arbitrary pattern. The moiré supercell crystal structures of c pristine TBG and b restructured TBG with torsional PLD model. Red and blue overlay highlights energetically unfavorable AA stacked region, and stable AB/BA stacked region, respectively. PLD decreases the total energy of the system by expanding AB/BA domain and decreasing the AA domain. Crystal structure of d AB stacked and e AA stacked bilayer graphene are shown as a reference.
