Orfanakis, KonstantinosRajendran, Sai KiranWalther, ValentinVolz, ThomasPohl, ThomasOhadi, Hamid2023-08-152022-04-14Orfanakis, Konstantinos, Sai Kiran Rajendran, Valentin Walther, Thomas Volz, Thomas Pohl, Hamid Ohadi. "Rydberg exciton–polaritons in a Cu2O microcavity." Nat. Mater. 21, no. 7 (2022): 767-772. DOI: 10.1038/s41563-022-01230-41476-11221476-4660https://nrs.harvard.edu/URN-3:HUL.INSTREPOS:37376794Giant Rydberg excitons with principal quantum numbers as high as $n=25$ have been observed in cuprous oxide (Cu$_2$O), a semiconductor where the exciton diameter can become as large as a micrometre. The giant dimension of these excitons results in excitonic interaction enhancements of orders of magnitude. Rydberg exciton-polaritons, formed by the strong coupling of Rydberg excitons to cavity photons, are a promising route to exploit these interactions and achieve a scalable, strongly correlated solid-state platform. However, the strong coupling of these excitons to cavity photons has remained elusive. Here, by embedding a thin Cu$_2$O crystal into a Fabry-Pérot microcavity, we achieve strong coupling of light to Cu$_2$O Rydberg excitons up to $n=6$ and demonstrate the formation of Cu$_2$O Rydberg exciton-polaritons. These results pave the way towards realising strongly interacting exciton-polaritons and exploring strongly correlated phases of matter using light on a chip.en-USMechanical EngineeringMechanics of MaterialsCondensed Matter PhysicsGeneral Materials ScienceGeneral ChemistryJournal Article2023-08-1510.1038/s41563-022-01230-4