Scientific Reports

We report on the observation of complex superlattices at the surface of the topological insulator Bi2Te3. Scanning tunneling microscopy reveals the existence of two different periodic structures in addition to the Bi2Te3 atomic lattice, which is found to strongly affect the local electronic structure. These three different periodicities are interpreted to result from a single small in-plane rotation of the topmost quintuple layer only. Density functional theory calculations support the observed increase in the DOS near the Fermi level, and exclude the possibility that strain is at the origin of the observed Moire pattern. Exploration of Moire superlattices formed by the quintuple layers of topological insulators holds great potential for further tuning of the properties of topological insulators. Research Foundation - Flanders (FWO, Belgium); Flemish Concerted Research Action program (BOF KU Leuven) [GOA/14/007]; China Scholarship Council [2011624021]; FWO; U.S. National Science Foundation [DMR-1206354]; San Diego Supercomputer Center (SDSC) Trestles [DMR060009N]; National Key Projects for Basic Research of China [2013CB922103]; National Natural Science Foundation of China [91421109, 11522432]; PAPD project; Natural Science Foundation of Jiangsu Province [BK20130054] The research in Leuven and Antwerp has been supported by the Research Foundation - Flanders (FWO, Belgium). The research in Leuven received additional support from the Flemish Concerted Research Action program (BOF KU Leuven, Project No. GOA/14/007). Z.L. thanks the China Scholarship Council for financial support (No. 2011624021). K.S. acknowledges support from the FWO. K.P. was supported by U.S. National Science Foundation DMR-1206354 and San Diego Supercomputer Center (SDSC) Trestles under DMR060009N. T.C. and F.S. acknowledge the financial support of the National Key Projects for Basic Research of China (Grant Nos: 2013CB922103), the National Natural Science Foundation of China (Grant Nos: 91421109, 11522432), the PAPD project, and the Natural Science Foundation of Jiangsu Province (Grant BK20130054).