Transition metal dichalcogenide (TMD) monolayers, such as molybdenum diselenide (MoSe2), represent a new class of semiconductors exhibiting novel features such as strong Coulomb interactions and efficient light-matter coupling. These two features together with fast improvement of sample quality ensured the demonstration of an atomically thin mirror. More generally, van der Waals heterostructures, composed of such atomically thin semiconducting mirrors, graphene, ferromagnetic CrI3 and insulating boron nitride, constitute a rich playground for investigation of many body physics and realization of novel device concepts.
