Fabrication, energy band engineering, and strong correlations of two-dimensional van der Waals moiré superlattices

The emerging properties of twisted bilayer graphene triggered extensive exploration of van der Waals (vdW) moire superlattices. Correlated insulating states, unconventional superconductivity, ferromagnetism, quantized anomalous Hall effect, ferroelectricity, and Pomeranchuk effect endow moire superlattices great potential for manufacturing electronic and quantum computation devices. These exotic properties may originate from the electronic many-body interactions in substantially narrow flat bands. A comprehensive qualitative understanding of vdW moire superlattices is critical. Herein, fabrication, characterization, energy band engineering, and strong electronic correlation properties of vdW moire superlattices are reviewed. The fabrication and characterization are prerequisites for the investigation of exact moire superlattices structures. Top-down and bottom-up methods are overviewed comprehensively. The confirmation of twist angles, the visualization of moire superlattices, and the observation of electronic band structures are described. In addition, energy band structure is a key factor in understanding the exceptional properties. Energy band engineering can be modified via twist angles, stacking configurations, pressure, strain, and so forth. Finally, strongly correlated properties and development priorities are discussed for manifesting the bright future of tunable vdW moire superlattices.

Automated summary

The twisted bilayer graphene vdW moire superlattices exhibit exotic properties such as correlated insulating states and unconventional superconductivity, making them promising for electronic and quantum computation device manufacturing. This review discusses the fabrication, characterization, energy band engineering, and strong electronic correlation properties of vdW moire superlattices, highlighting the importance of a comprehensive understanding of these structures.