Colloidal nanocrystals: Viable model systems for electronic quantum materials?

The field of colloidal nanocrystals has witnessed enormous progress in the last three decades. For many families of nanocrystals, wet-chemical syntheses have been developed that allow control over the crystal shape and dimensions, from the three-dimensional down to the zero-dimensional case. Additionally, careful control of surface chemistry has enabled the prevention of non-radiative recombination, thus allowing the detailed study of confined charge carriers and excitons. This has led to a vast amount of applications of nanocrystals in displays, labels, and lighting. Here, we discuss how this expertise could benefit the rapidly advancing field of quantum materials, where the coherence of electronic wave functions is key. We demonstrate that colloidal two-dimensional nanocrystals can serve as excellent model systems for studying topological phase transitions, particularly in the case of quantum spin Hall and topological crystalline insulators. We aim to inspire researchers with strong chemical expertise to explore the exciting field of quantum materials. (Figure presented.)