Two dimensional covalent moire superlattice from fluorinating twisted bilayer graphene

TL;DR

This paper demonstrates that fluorinating twisted bilayer graphene creates covalent bonds between layers, forming a new type of moire superlattice with flat electronic bands, opening avenues for studying correlated quantum phenomena.

Contribution

It introduces a novel method to construct covalent moire superlattices via fluorination, transforming interlayer interactions from van der Waals to covalent bonds.

Findings

Fluorination induces covalent bonds between graphene layers.

Results in flat electronic bands across the spectrum.

Provides a new platform for exploring correlated quantum phenomena.

Abstract

Moire materials exhibit diverse quantum properties such as superconductivity and correlated topo logical phases, making them ideal for studying strongly correlated systems. While moire materials are typically formed by stacking two-dimensional materials with interlayer interaction dominated by weak van der Waals (vdW) forces, we explore the possibility for constructing moire covalent super lattices by fluorinating twisted bilayer graphene. With first principle calculations, we demonstrate that fluorination of twisted bilayer graphene (TBG) can induce covalent bonds between adjacent layers, transforming the vdW-dominated interactions. This results in enhanced modulation of the electronic structure, with abundant flat bands across the spectrum. Our findings suggest that cova lent moire superlattices offer new platforms for exploring correlated quantum phenomena and moire covalent chemistry.