Plexcitonic strong coupling: unique features, applications, and challenges
Abstract There are, recently, remarkable achievements in turning light-matter interactions into strong coupling quantum regime. In particular, room temperature plexcitonic strong coupling in plasmon-exciton hybrid systems can bring promising benefits for fundamental and applied physics. Herein we will review theoretical insights and recent experimental achievements in plexcitonic strong coupling and divide this review into two main parts. The first part will briefly introduce the general field of strong coupling, including its origin and history, physical mechanisms and theoretical models, as well as recent advanced applications of strong coupling, such as the quantum or biochemical devices enabled by optical strong coupling. The second part will zoom in and concentrate on plexcitonic strong coupling by introducing its unique features and new potentials (such as single-particle ultrastrong coupling, strong coupling dynamics in femtosecond scale) and discussing the limitations and challenges of plexcitonic strong coupling, which will also be accompanied by potential solutions such as the microcavity-engineered plexcitonics, spectral hold burning effects, and metamaterial-based strong coupling. Finally, we will summarize and conclude this review, highlighting the future research directions and promising applications.