Since their recent discovery in 2014, Rydberg excitons (large principal quantum number n ~ 10 – 30) have become fascinating objects to study strongly correlated systems and non-linear quantum optics, due to their giant dipolar moment. Indeed, the physics of Rydberg excitons is similar to the well known Rydberg atoms. In particular, their scaling laws are as extreme (polarisability in n^7, interactions in n^11), promising giant and well controlled interactions in a solid. This has a double interest, both fondamental and for quantum technologies in a semiconductor.

Our team currently studies the fundamental properties of different semiconductors presenting Rydberg excitons (copper oxide, type TMD 2D materials and inorganic perovskite) probing them with mid-infrared or teraherz radiation, in two-colours experiments. These radiations correspond to the typical transition energies between Rydberg states, enabling the study of ill-known dark states and to explore their potential for optical coherent control. The diversity of materials offer collaboration opportunities within LPENS (ex. perovskites) and outside (copper oxide, 2D materials). Moreover, original structures such as high-finesse THz microcavities developed in our team and fiber-tip microcavities developped by the Nano-optics team (in collaboration with LKB) will be used to both boost light-matter interaction and confine the system, an important step toward coherent control at a very small particles number (single photon / exciton).

This project has received financial support from Agence Nationale de la Recherche (ANR JCJC “PIONEEReX”) and from DIM Sirteq (project NOTOROUS).