Physical properties of novel electronic states related to flat band in twisted two-dimensional quantum materials br

Two-dimensional (2D) materials can exhibit novel quantum phenomena and be easily tuned by the externalenvironment, which has made them one of the most attractive topics in condensed matter physics during therecent decades. The moire superlattice induced by varied stacking geometry can further renormalize thematerial band structure, resulting in the electronic flat bands. With the help of external fields, one can tune theelectron-electron correlated interaction in these flat bands, even control the overall physical properties. In thispaper we review the recent researches of novel properties in twisted 2D materials (graphene and transitionmetal dichalcogenide heterostructure), involving strong correlation effect, unconventional superconductivity,quantum anomalous Hall effect, topological phase, and electronic crystals. We also discuss some open questions and give further prospects in this field