Localized polariton states in a photonic crystal intercalated by a transition metal dichalcogenide monolayer

TL;DR

This paper theoretically investigates two types of localized exciton-polariton modes in a photonic crystal with an embedded TMD monolayer, revealing their distinct properties and proposing an experimental detection method.

Contribution

It introduces a theoretical framework for localized polariton modes in photonic crystals with TMD monolayers, identifying two distinct types and their dispersion relations.

Findings

Localized modes occur in zeroth- and first-order stop-bands.

First type of mode appears inside the light cone and couples TMD excitons with optical Tamm states.

Proposed experimental detection and numerical simulation of these modes.

Abstract

Beyond the extensively studied microcavity polaritons, which are coupled modes of semiconductor excitons and microcavity photons, nearly 2D semiconductors placed in a suitable environment can support spatially localized exciton-polariton modes. We demonstrate theoretically that two distinct types of such modes can exist in a photonic crystal with an embedded transition metal dichalcogenide (TMD) monolayer and derive an equation that determines their dispersion relations. The localized modes of two types occur in the zeroth- and first-order stop-bands of the crystal, respectively, and have substantially different properties. The latter type of the localized modes, which appear inside the light cone, can be described as a result of coupling of the TMD exciton and an optical Tamm state of the TMD-intercalated photonic crystal. We suggest an experiment for detecting these modes and simulate it numerically.