title: Room-temperature exciton-polaritons with two-dimensional WS2.
abstract: Two-dimensional transition metal dichalcogenides exhibit strong optical transitions with significant potential for optoelectronic devices. In particular they are suited for cavity quantum electrodynamics in which strong coupling leads to polariton formation as a root to realisation of inversionless lasing, polariton condensation and superfluidity. Demonstrations of such strongly correlated phenomena to date have often relied on cryogenic temperatures, high excitation densities and were frequently impaired by strong material disorder. At room-temperature, experiments approaching the strong coupling regime with transition metal dichalcogenides have been reported, but well resolved exciton-polaritons have yet to be achieved. Here we report a study of monolayer WS2 coupled to an open Fabry-Perot cavity at room-temperature, in which polariton eigenstates are unambiguously displayed. In-situ tunability of the cavity length results in a maximal Rabi splitting of ħΩRabi = 70 meV, exceeding the exciton linewidth. Our data are well described by a transfer matrix model appropriate for the large linewidth regime. This work provides a platform towards observing strongly correlated polariton phenomena in compact photonic devices for ambient temperature applications.
authors.affiliation: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom.
authors.forename: L C
authors.initials: LC
authors.lastname: Flatten
authors.affiliation: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom.
authors.forename: Z
authors.initials: Z
authors.lastname: He
authors.affiliation: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom.|Clarendon Laboratory, Department of Physics, University of Oxford, OX1 3PU, United Kingdom.
authors.forename: D M
authors.initials: DM
authors.lastname: Coles
authors.affiliation: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom.
authors.forename: A A P
authors.initials: AA
authors.lastname: Trichet
authors.affiliation: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom.
authors.forename: A W
authors.initials: AW
authors.lastname: Powell
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford, OX1 3PU, United Kingdom.
authors.forename: R A
authors.initials: RA
authors.lastname: Taylor
authors.affiliation: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom.
authors.forename: J H
authors.initials: JH
authors.lastname: Warner
authors.affiliation: Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom.
authors.forename: J M
authors.initials: JM
authors.lastname: Smith