This study investigates spatial and temporal variations in the moiré pattern of twisted bilayer graphene (TBG) using aberration-corrected Low Energy Electron Microscopy (AC-LEEM). The researchers found smaller spatial variations than previously reported and observed thermal fluctuations corresponding to collective atomic displacements. No untwisting was observed up to 600°C, suggesting thermal annealing can reduce local disorder. Edge dislocations in the underlying atomic lattice were also observed, with the moiré structure acting as a magnifier, potentially exhibiting unique local electronic properties.

Tobias A. de Jong, Tjerk Benschop, Xingchen Chen, Eugene E. Krasovskii, Michiel J. A. de Dood, Rudolf M. Tromp, Milan P. Allan, Sense Jan van der Molen