Interlayer excitons (IXs) in heterostructures of layered materials are quasiparticles in which electrons and holes are confined to different layers while remaining strongly bound. Their spatial separation gives IXs long lifetimes, allowing them to move over larger distances and interact with one another. This separation also creates a permanent out-of-plane electric dipole, which enables the manipulation of their optical properties using an external electric field. 

Using a custom-built cryogenic spectroscopy setup, in our group we probe the optical response of interlayer excitons in high-quality heterostructures. These experiments are complemented by theoretical modeling, providing insights into how interlayer excitons interact with light and how their optical properties can be controlled. These studies contribute to a deeper understanding of interlayer excitons and their collective behavior, with potential relevance for future optoelectronic and quantum technologies.