2024/10/10 by Chi Shing Tsang, Xiaodong Zheng, Tong Yang +12 · 9 citations
Engineering · Materials Science · #Chalcogenide Semiconductor Thin Films #2D Materials and Applications #Phase-change materials and chalcogenides
paper · doi:10.1126/science.adp7099
) and elucidate its correlation with local polar domains using four-dimensional scanning transmission electron microscopy (4D-STEM) and first-principles calculations. We reveal the emergence of in-plane topological vortices within the periodic moiré patterns for both commensurate structures at small twist angles and the incommensurate quasicrystal structure that occurs at a 30° twist. The large-angle twist leads to mosaic chiral vortex patterns with tunable characteristics. A twisted quasicrystal bilayer, characterized by its 12-fold rotational symmetry, hosts complex vortex patterns and can be manipulated by picometer-scale interlayer displacement. Our findings highlight that twisting 2D bilayers is a versatile strategy for tailoring local electric polar vortices.