Synthesis of incommensurate moiré structures with short-range-ordered charge density modulation.

Abstract

Moiré structures have attracted great interest for tuning emergent quantum phenomena and enabling novel device functionalities. For the twisted bilayer graphene or semiconducting transition-metal dichalcogenides, studies have been focused on ordered systems, atomically and electronically. However, disordered/short-range-ordered moiré electronic structures, likewise involving emergence of novel physical properties and functional applications, remain elusive. Here, we report an incommensurate moiré structure with short-range-ordered charge density modulation state, which is formed between monolayer metallic NiTe₂ and superconductor NbSe₂. This state features intra-moiré-cell irregular charge orders with spontaneous on-site ordering at the moiré scale, while breaking the crystalline symmetries at the atomic scale. The short-range charge order likely originates from enhanced electron correlations driven by the cooperative effect of moiré-confined strain and localization of electron density. Furthermore, with the layers of NiTe₂, we have successfully tuned the short-range state. Our findings provide a promising platform for exploring novel electronic states beyond conventional Bloch-based frameworks and potential applications in quantum devices.