Emerging chirality and moir\'e dynamics in twisted layered material heterostructures

TL;DR

This paper predicts the emergence of chiral distortions in twisted layered 2D materials, revealing how interfacial interactions and boundary constraints induce dynamic chirality and influence twisting behavior.

Contribution

It introduces the concept of fractional chiral area to quantify chirality and demonstrates the spontaneous transition from stick-slip to smooth rotation in moiré structures.

Findings

Chiral distortions emerge due to interfacial interactions and boundary constraints.

A new metric, fractional chiral area, quantifies overall chirality.

Twisting dynamics show a transition from stick-slip to smooth rotation without external triggers.

Abstract

Moir\'e superstructures arising at twisted 2D interfaces have recently attracted the attention of the scientific community due to exotic quantum states and unique mechanical and tribological behaviors that they exhibit. Here, we predict the emergence of chiral distortions in twisted layered interfaces of finite dimensions. This phenomenon originates in intricate interplay between interfacial interactions and contact boundary constraints. A metric termed the fractional chiral area, is introduced to quantify the overall chirality of the moir\'e superstructure and to characterize its spatial distribution. Despite the equilibrium nature of the discovered energetic and structural chirality effects they are shown to be manifested in the twisting dynamics of layered interfaces, which demonstrates a continuous transition from stick-slip to smooth rotation with no external trigger.