Intrinsic One-Dimensional Moiré Superlattice in Large-Angle Twisted Bilayer WTe₂.

Abstract

Moiré effects in two-dimensional (2D) twisted van der Waals structures are attracting great interest owing to the emergence of intriguing physical properties. Despite growing interests, moiré effects with large twist angles remain unexplored because the increase of twist angle is thought to quickly suppress the size of moiré patterns. In this study, we focused on large-angle twisted tungsten ditelluride and discovered two orthogonal one-dimensional (1D) moiré patterns at twist angles around 62° and 58° using transmission electron microscopy. Their diffraction patterns exhibited pair formation features supporting the one-dimensionality of these moiré patterns. We also succeeded in revealing the origin of large-angle moiré patterns as well as the intrinsic nature of 1D moiré patterns. The observed moiré patterns are purely 1D in the sense that the long-range periodicity exists only along one direction, being a promising platform to study 1D phenomena. Our results propose a universal concept for studying large-angle twisted structures.