Strong coupling in a two-dimensional semiconductor/noble metal multilayer platform

Abstract

We investigate the Purcell factor and emission spectrum of a two-level quantum emitter placed near a planar multilayer nanostructure composed of an ultrathin dielectric or noble metal film between a pair of two-dimensional (2D) layers of transition-metal dichalcogenides. We focus on the 2D semiconductor layer of WS_{2}. Experimental values for the dielectric permittivity of the WS_{2} and the Au, Ag, Cu, and Al noble metals are used for computing their optical response. The Purcell factor of the quantum emitter near such a nanostructure takes values above 10^{4}. The emission spectrum of the quantum emitter features profound Rabi splittings at the visible part of the spectrum at room temperature indicating the emergence of the strong light-matter coupling regime. The emission spectrum of the quantum emitter is strongly influenced by the dielectric permittivity of the host medium and the material quality of the noble metal. Our research paves the way for applications in quantum technologies and biosensors.