10.06.2022 Moiré Exciton Polaritons in twisted materials (published in Nano Letters)

Twisted atomically thin semiconductors are characterized by moire excitons. Their hybridization with photons in the strong coupling regime for heterostructures integrated in an optical cavity has not been well understood yet. In this work, we combined an excitonic density matrix formalism with a Hopfield approach to provide microscopic insights into moire exciton polaritons. In particular, they show that exciton-light coupling, polariton energy, and even the number of polariton branches can be controlled via the twist angle. These new hybrid light-exciton states become delocalized relative to the constituent excitons due to the mixing with light and higher-energy excitons. The system can be interpreted as a natural quantum metamaterial with a periodicity that can be engineered via the twist angle. The work has been published in Nano Letters.

Nano Letters 11, 4468 (2022)