[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Ultrastrong coupling of plasmonic metamaterials and photons in a terahertz photonic crystal cavity

摘要： Light-matter interaction in the strong coupling regime is of profound interest for fundamental quantum optics and applications. Here, we report a new type of strong light-matter interaction of metamaterial ‘quasi-particles’ with photons in a photonic crystal cavity in the terahertz frequency range. The measured Rabi splitting shows a square-root dependence on the density of metamaterial unit cells, even for unit cells from two spatially separated planar metamaterials, indicating nonlocal collective strong interactions. These findings are of interest for the investigation of fundamental strong-coupling phenomena, but also for applications such as ultra-low-threshold terahertz polariton lasing, voltage-controlled modulators and frequency filters, and ultra-sensitive chemical and biological sensing.