Exciton-surface plasmon polariton interactions

ABSTRACT Exciton-surface plasmon polariton (exciton-SPP) interactions in semiconductor-metal hybrid nanostructures connect two fundamentally different quantum mechanical excitations with strikingly different dispersion relations and optical response. The main focus in investigating these light–matter interactions and nanostructures is to control the light via light on the nanometric length scale and ultrafast timescale, not achievable by present photonic or electronic technologies. Here, we provide a concise description of the relevant background physics and an overview of the manifestations, challenges and applications of weak and strong exciton-SPP interactions. It is now well established that semiconductor-metal hybrid nanostructures offer exciting opportunities to investigate intriguing quantum phenomena and many-body interactions in condensed matter systems even at room temperature. We also review how exciton-SPP interactions have been influencing various research directions. It is amply evident that a comprehensive understanding of these interactions may play an important role in several research areas. The recent progress made in this field is expected to give rise to novel applications of active plasmonic structures. Synopsis The ability of surface plasmon polaritons to localize light on the nanoscale dimensions results in a strong field enhancement, enabling efficient intensification of light–matter interaction with excitons in semiconductors. Two interaction regimes, weak and strong coupling are identified. Both these regimes exhibit intriguing quantum mechanical physical effects and are promising for diverse applications. Interestingly, unlike in pure atomic systems, in semiconductor-metal hybrid structures, these quantum-optical effects are observable even at room temperature. Graphical Abstrac