Layered materials can be assembled vertically to fabricate a new class of van der Waals (VDW) heterostructures a few atomic layers thick, compatible with a wide range of substrates and optoelectronic device geometries, enabling new strategies for control of light-matter coupling. Here, we incorporate molybdenum diselenide/boron nitride (MoSe2/hBN) quantum wells (QWs) in a tunable optical microcavity. Part-light-part-matter polariton eigenstates are observed as a result of the strong coupling between MoSe2 excitons and cavity photons, evidenced from a clear anticrossing between the neutral exciton and the cavity modes with a splitting of 20 meV for a single MoSe2 monolayer QW, enhanced to 29 meV in MoSe2/hBN/MoSe2 double-QWs. The splitting at resonance provides an estimate of the exciton radiative lifetime of 0.4 ps. Our results pave the way for room temperature polaritonic devices based on multiple-QW VDW heterostructures, where polariton condensation and electrical polariton injection through the incorporation of graphene contacts may be realised.
@article{arxiv.1505.04438,
title = {Exciton-polaritons in van der Waals heterostructures embedded in tunable microcavities},
author = {S. Dufferwiel and S. Schwarz and F. Withers and A. A. P. Trichet and F. Li and M. Sich and O. Del Pozo-Zamudio and C. Clark and A. Nalitov and D. D. Solnyshkov and G. Malpuech and K. S. Novoselov and J. M. Smith and M. S. Skolnick and D. N. Krizhanovskii and A. I. Tartakovskii},
journal= {arXiv preprint arXiv:1505.04438},
year = {2015}
}