Electronic crystals in layered materials

Abstract: In modern two-dimensional (2D) materials, such as graphene-based systems and atomically-thin transition-metal dichalcogenides, the interplay of strong electronic correlations, tunable moir\'e superlattices, and nontrivial band topology has given rise to rich phase diagrams and collective phenomena. Among the novel phases that have been realized, electronic crystals -- states of matter in which itinerant electrons spontaneously crystallize -- play a particularly prominent role. In this Review, we summarize the current status of electron crystallization in van der Waals heterostructures, with emphasis on the experimental platforms and measurement techniques that enable their study. We also highlight open questions and outline future directions that may elucidate more of the fascinating properties of electronic crystals.