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

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Moiré effects in two-dimensional (2D) twisted van der Waals structures exhibit fascinating physical properties.
• Research on moiré effects has primarily focused on small twist angles, with large angles largely unexplored due to the perceived suppression of moiré pattern size.

Purpose of the Study:

• To investigate moiré effects in large-angle twisted van der Waals structures.
• To explore the possibility of moiré patterns at large twist angles and understand their characteristics.

Main Methods:

• Focused on large-angle twisted tungsten ditelluride.
• Utilized transmission electron microscopy (TEM) to observe and analyze moiré patterns.
• Examined diffraction patterns to confirm the dimensionality of the observed moiré structures.

Main Results:

• Discovered two orthogonal one-dimensional (1D) moiré patterns in tungsten ditelluride at twist angles around 62° and 58°.
• Diffraction patterns provided evidence supporting the one-dimensional nature of these moiré patterns.
• Elucidated the origin of these large-angle moiré patterns and their intrinsic 1D characteristics.

Conclusions:

• The observed purely 1D moiré patterns, with periodicity along a single direction, offer a novel platform for studying 1D phenomena.
• These findings challenge the notion that large twist angles suppress moiré patterns and propose a universal concept for analyzing large-angle twisted structures.