Due to high binding energy and oscillator strength, excitons in thin flakes of transition metal dichalcogenides constitute a perfect foundation for realizing a strongly coupled light-matter system. In this paper we investigate mono- and few-layer WSe2 flakes encapsulated in hexagonal boron nitride and incorporated into a planar dielectric cavity. We use an open cavity design which provides tunability of the cavity mode energy by as much as 150 meV. We observe a strong coupling regime between the cavity photons and the neutral excitons in direct-bandgap monolayer WSe2, as well as in few-layer WSe2 flakes exhibiting indirect bandgap. We discuss the dependence of the exciton's oscillator strength and resonance linewidth on the number of layers and predict the exciton-photon coupling strength.
@article{arxiv.1908.05300,
title = {Exciton-polaritons in multilayer WSe$_2$ in a planar microcavity},
author = {M. Król and K. Rechcińska and K. Nogajewski and M. Grzeszczyk and K. Łempicka and R. Mirek and S. Piotrowska and K. Watanabe and T. Taniguchi and M. R. Molas and M. Potemski and J. Szczytko and B. Piętka},
journal= {arXiv preprint arXiv:1908.05300},
year = {2019}
}