Polar and quasicrystal vortex observed in twisted-bilayer molybdenum disulfide

• 成果类型: Article
• 署名作者: Tsang, Chi Shing; Zheng, Xiaodong; Yang, Tong; Yan, Zhangyuan; Han, Wei; Wong, Lok Wing; Liu, Haijun; Gao, Shan; Leung, Ka Ho; Lee, Chun-Sing; Lau, Shu Ping; Yang, Ming; Zhao, Jiong; Ly, Thuc Hue
• 署名单位: Hong Kong Polytechnic University; City University of Hong Kong; City University of Hong Kong; Hong Kong Polytechnic University; City University of Hong Kong; City University of Hong Kong; Shenzhen Research Institute, City University of Hong Kong; Hong Kong Polytechnic University; Hong Kong Polytechnic University; Hong Kong Polytechnic University
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10158
• DOI: 10.1126/science.adp7099
• 发表日期: 2024-10-01
• 页码: 198-205
• 关键词: graphene

摘要

We report the observation of an electric field in twisted-bilayer molybdenum disulfide (MoS2) 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 moir & eacute; patterns for both commensurate structures at small twist angles and the incommensurate quasicrystal structure that occurs at a 30 degrees 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.