Toward Molecular Chiral Polaritons

Coupling between light and material excitations underliesa widerange of optical phenomena. Polaritons are eigenstates of a coupledsystem with a hybridized wave function. Owing to their hybrid composition,polaritons exhibit at the same time properties typical for photonicand electronic excitations, thus offering new ways for controllingelectronic transport and even chemical kinetics. While most theoreticaland experimental efforts have been focused on polaritons with electric-dipolecoupling between light and matter, in chiral quantum emitters, electronictransitions are characterized by simultaneously nonzero electric andmagnetic dipole moments. Thus, it is natural to wonder what kindsof novel effects chirality may enable in the realm of strong light-mattercoupling. Right now, this field located at the intersection of nanophotonics,quantum optics, and chemistry is in its infancy. In this Perspective,we offer our view toward chiral polaritons. We review basic physicalconcepts underlying chirality of matter and electromagnetic field,discuss the main theoretical and experimental challenges that needto be solved, and consider novel effects that could be enabled bystrong coupling between chiral light and matter.