Analytical formalism for the interaction of two-level quantum systems with metal nanoresonators

Hybrid systems made of quantum emitters and plasmonic nanoresonators offer a unique platform to implement artificial atoms with completely novel optical responses that are not available otherwise. However, their theoretical analysis is difficult and since many degrees of freedom have to be explored, engineering their optical properties remains challenging. Here we propose a new formalism which removes most limitations encountered in previous analytical treatments and allows a flexible and efficient study of complex nanoresonators with arbitrary shapes in an almost fully analytically way. The formalism brings accurate closed-form expressions for the hybrid-system optical response, and provides an intuitive description based on the coupling between the quantum emitters and the resonance modes of the nanoresonator. The ability to quickly predict light scattering properties of hybrid systems paves the way to a deep exploration of their fascinating properties and may enable rapid optimization of quantum plasmonic metamaterials or quantum information devices