Plasmon-exciton polaritons in 2D semiconductor/metal interfaces

TL;DR

This paper explores how plasmon-exciton polaritons can be generated and controlled in 2D semiconductor/metal interfaces, enabling strong coupling and tunable optical properties for advanced photonic devices.

Contribution

It demonstrates the realization and tuning of plasmon-exciton polaritons in 2D TMDC/metal structures with Rabi splittings over 100 meV at room temperature.

Findings

Strong coupling regime achieved with Rabi splitting >100 meV.

Tuning of polaritonic interactions via dielectric layer and metal film thickness.

Potential for compact, tunable photonic devices.

Abstract

The realization and control of polaritons is of paramount importance in the prospect of novel photonic devices. Here, we investigate the emergence of plasmon-exciton polaritons in hybrid structures consisting of a two-dimensional (2D) transition metal dichalcogenide (TMDC) deposited onto a metal substrate or coating a metallic thin-film. We determine the polaritonic spectrum and show that, in the former case, the addition of a top dielectric layer, and, in the latter, the thickness of the metal film,can be used to tune and promote plasmon-exciton interactions well within the strong coupling regime. Our results demonstrate that Rabi splittings exceeding 100 meV can be readily achieved in planar dielectric/TMDC/metal structures under ambient conditions. We thus believe that this work provides a simple and intuitive picture to tailor strong coupling in plexcitonics, with potential applications for engineering compact photonic devices with tunable optical properties.