Enhanced Rabi Splitting in Organic and Two-Dimensional Material Optical Cavities

On April 13, 2025, researchers V. G. M. Duarte, A. J. Chaves, and N. M. R. Peres published a study titled Organic-Inorganic Polaritonics: Linking Frenkel and Wannier-Mott Excitons, detailing the creation of hybrid exciton-polaritons in an optical cavity combining organic molecules with 2D tungsten sulfide. Their work demonstrates enhanced Rabi splitting, offering new possibilities for exploring light-matter interactions in quantum materials.

The study explores the interaction between two-dimensional (2D) materials and organic molecular aggregates in an optical cavity, predicting the formation of hybrid Wannier-Mott-Frenkel exciton-polaritons with enhanced Rabi splitting. Using tungsten sulfide and a cyanine dye as a model system, the research demonstrates that this hybrid state achieves a significant increase in Rabi splitting compared to pure organic cavities. The complementary properties of Wannier-Mott and Frenkel excitons enable tunable polariton states that merge into a single hybrid state under detuning, supporting dual Rabi splitting mechanisms. This platform offers new opportunities for studying optical phenomena across strong and ultrastrong coupling regimes.

Excitons can be categorized into two types: Wannier-Mott and Frenkel. Wannier-Mott excitons occur in semiconductors where electrons and holes are tightly bound, while Frenkel excitons are found in organic materials, characterized by weaker binding. The interaction between these excitons and photons within confined spaces is a key area of research, as it holds the potential to unlock new functionalities in quantum systems.

Strong coupling between light and matter can be achieved using high-quality nanocavities with long photon lifetimes. These cavities minimize photon loss, enabling prolonged interactions between light and matter. By embedding quantum materials like van der Waals heterostructures within these cavities, researchers can precisely control exciton properties. Van der Waals heterostructures, composed of layered materials such as transition metal dichalcogenides (TMDs), offer versatility in electronic properties, making them ideal for studying exciton-photon interactions.

One of the main challenges in achieving strong coupling is maintaining high-quality cavities to reduce photon loss. Additionally, selecting materials that enhance exciton-photon interactions is crucial. The use of van der Waals heterostructures and TMDs addresses these issues by providing a platform where excitons can be manipulated with precision.

The implications of this research are vast. By steering room-temperature plexcitonic strong coupling, which involves multiple excitons interacting with photons, scientists can develop more efficient light-emitting diodes (LEDs) and advanced sensors. Furthermore, these findings pave the way for quantum computing components that leverage exciton-photon interactions for information processing.

The study of quantum materials and their interaction with light is unlocking new possibilities in technology. By understanding and manipulating excitons within high-quality nanocavities, researchers are paving the way for innovations in optoelectronics, sensing, and quantum computing. As this field continues to evolve, it promises to revolutionize how we interact with light and matter at a fundamental level, leading to technologies that were once only imagined.