Recent Advances in Twisted Structures of Flatland Materials and Crafting Moire Superlattices

The past decade has witnessed the occurrence of novel 2D moire patterns in nanoflatland materials. These visually beautiful moire superlattices have become a playground on which exotic quantum phenomena can be observed. The state-of-the-art experimental techniques that have been developed for crafting moire superlattices of flatland materials are reviewed. Graphene and its heterostructure with boron nitride have now sparked new interlayer twists as a new degree of freedom for tuning several angle-dependent physical properties, e.g., the appearance of van Hove singularities, tunable Mott insulator states, and the Hofstadter butterfly pattern. Moreover, the interplay of correlated insulating states and superconductivity is recently observed for a so-called magic-angle twisted bilayer graphene. Furthermore, beyond graphene, other 2D materials, such as silicene, phosphorene, and the recent black phosphorus /MoS(2)heterojunctions, which are 2D allotropes of bismuth and antimony grown on highly ordered pyrolytic graphite and MoS2, are considered. Finally, the optically important exciton phenomenon, which depends on the moire potential and has been observed for a moire superlattice of transition metal dichalcogenides, is discussed. This overview aims to cover all the fascinating prospects that depend on the moire superlattice, ranging from electronic structure to optical exotics among flatland materials.