Engineering light–matter interactions
up to the strong-coupling
regime at room temperature is one of the cornerstones of modern nanophotonics.
Achieving this goal could enable new platforms for potential applications
such as quantum information processing, quantum light sources, and
even quantum metrology. Layered materials like transition metal dichalcogenides
(TMDCs) and, in particular, tungsten disulfide (WS2), possess
strong dipole moments which are comparable to semiconductor-based
quantum dots, but the former also exhibit large exciton binding energies,
thereby making TMDCs suitable candidates for exploring light–matter
interactions at ambient conditions. Furthermore, the combination of
TMDCs with plasmonic nanocavities, which tightly confine light down
to nanometer scale, has recently emerged as a suitable platform for
achieving strong coupling between plasmons and excitons at room temperature.
Here, we use ultrathin single-crystalline gold nanodisks featuring
large in-plane electric dipole moments aligned with the exciton’s
dipole moments in monolayer WS2. By performing both scattering
and reflection spectroscopy, we demonstrate strong coupling at room
temperature with a Rabi splitting of ∼108 meV. In addition,
when the plasmonic resonance of these nanodisks is coupled with few-layer
WS2, a Rabi splitting of ∼175 meV is observed,
with a major increase of 62% relative to the monolayer configuration.
Our results therefore suggest that ultrathin single-crystalline gold
nanodisks coupled to WS2 constitute an attractive platform
to explore light–matter interactions in the strong-coupling
- Strong coupling
- Gold nanodisks
Geisler, M., Cui, X., Wang, J., Rindzevicius, T., Gammelgaard, L.
, Jessen, B. S., ... Stenger, N.
(2019). Single-Crystalline Gold Nanodisks on WS2 Mono- and Multilayers for Strong Coupling at Room Temperature
. ACS Photonics
, 994-1001. https://doi.org/10.1021/acsphotonics.8b01766