Two-dimensional (2D) twisted moiré materials, a new class of van der Waals (vdW) layered heterostructures with different twist angles between neighboring layers, have attracted tremendous attention due to their rich emerging properties. In this review, we systematically summarize the recent progress of 2D twisted moiré materials. Firstly, we introduce several representative fabrication methods and the fascinating topographies of the twisted moiré materials. Specifically, we discuss various remarkable physical properties related to twisted angles, including flat bands, unconventional superconductivity, ferromagnetism, and ferroelectricity. We also analyze the potential applications in various twisted moiré systems. Finally, the challenges and future perspectives of the twisted moiré materials are discussed. This work would spur edge-cutting ideas and related achievements in the scientific and technological frontiers of 2D twisted moiré materials.

Tomonaga–Luttinger liquid (TLL), a peculiar one-dimensional (1D) electronic behavior due to strong correlation, was first studied in 1D nanostructures and has attracted significant attention over the last several decades. With the rise of new two-dimensional (2D) quantum materials, 1D nanostructures in 2D materials have provided a new platform with a well-defined configuration at the atomic scale for studying TLL electronic behavior. In this paper, we review the recent progress of TLL electronic features in emerging 2D materials embedded with various 1D nanostructures, including island edges, domain walls, and 1D moiré patterns. Specifically, novel physical phenomena, such as 1D edge states in 2D transition metal dichalcogenides (TMDs), helical TLL in 2D topological insulators (2DTI), and chiral TLL in 2D quantum Hall systems, are described and discussed at the nanoscale. We also analyze challenges and opportunities at the frontier of this research area.

Understanding the influence of adsorption sites to the electronic properties of adsorbed molecules on two-dimensional (2D) ultrathin insulator is of essential importance for future organic-inorganic hybrid nanodevices. Here, the adsorption and electronic states of manganese phthalocyanine (MnPc) on a single layer of hexagonal boron nitride (h-BN) have been comprehensively studied by low-temperature scanning tunneling microscopy/spectroscopy and tight binding calculations. The frontier orbitals of the MnPc can change drastically by reversible manipulation of individual MnPc molecules onto and away from the single atomic vacancies at the h-BN surface. Particularly, the change of the molecular electronic configuration can be controlled depending on whether the atomic vacancy is below the metal center or the ligand of the MnPc. These findings give new insight into defect-engineering of the organic-inorganic hybrid nanodevices down to submolecular level.