A Quantum Leap for Light-Based Chips: First On-Chip Rydberg Polaritons

Researchers have achieved a significant breakthrough in quantum optoelectronics by demonstrating the first on-chip Rydberg exciton polaritons. These are hybrid particles—part light, part matter—that are highly prized for their strong optical nonlinearities, which allow them to interact vigorously with one another. Until now, creating these particles required bulky setups involving vertically stacked mirrors, making them unsuitable for compact integrated technologies.

In this new study, the team utilised a photonic crystal (PhC) architecture based on a monolayer of tungsten disulphide (WS₂). This design proved robust, with the particles surviving at temperatures up to 80 Kelvin. By moving away from traditional bulky mirrors to a flat, on-chip design, the researchers overcame a major hurdle in shrinking down quantum optical devices.

The performance gains were substantial. The study reports that these Rydberg polaritons exhibit a nonlinearity approximately eight times larger than standard ground-state polaritons. This enhancement is attributed to the extended radii of the Rydberg excitons—essentially, the particles are physically larger—and a more strongly localised electric field compared to previous geometries. This successful realisation represents a solid step towards future polaritonic-based integrated circuits, essential for advanced computing and signal processing.