Revealing Dark Exciton Signatures in Polariton Spectra of 2D Materials
Journal article, 2024
Dark excitons in transition metal dichalcogenides (TMDs) have been so far neglected in the context of polariton physics due to their lack of oscillator strength. However, in tungsten-based TMDs, dark excitons are known to be the energetically lowest states and could thus provide important scattering partners for polaritons. In this joint theoretical-experimental work, we investigate the impact of the full exciton energy landscape on polariton absorption and reflectance. By changing the cavity detuning, we vary the polariton energy relative to the unaffected dark excitons in such a way that we open or close specific phonon-driven scattering channels. We demonstrate both in theory and experiment that this controlled switching of scattering channels manifests in characteristic sharp changes in the optical spectra of polaritons. These spectral features can be exploited to extract the position of dark excitons. Our work suggests new possibilities for exploiting polaritons for fingerprinting nanomaterials via their unique exciton landscape.
transition metal dichalcogenides
polariton-dark exciton scattering
polaritonic absorption
cavity detuning
strong coupling
Author
Beatriz de Amorim Ferreira
Chalmers, Physics, Condensed Matter and Materials Theory
Hangyong Shan
The Carl von Ossietzky University of Oldenburg
Roberto Rosati
Philipps University Marburg
Jamie M. Fitzgerald
Philipps University Marburg
Lukas Lackner
The Carl von Ossietzky University of Oldenburg
Bo Han
The Carl von Ossietzky University of Oldenburg
Martin Esmann
The Carl von Ossietzky University of Oldenburg
Patrick Hays
Arizona State University
Gilbert Leibeling
Fraunhofer Society
Max Planck Society
Friedrich Schiller University Jena
Kenji Watanabe
National Institute for Materials Science (NIMS)
Takashi Taniguchi
National Institute for Materials Science (NIMS)
Falk Eilenberger
Fraunhofer Society
Max Planck Society
Friedrich Schiller University Jena
Sefaattin Tongay
Arizona State University
Christian Schneider
The Carl von Ossietzky University of Oldenburg
Ermin Malic
Philipps University Marburg
ACS Photonics
2330-4022 (eISSN)
Vol. 11 6 2215-2220Plasmon-exciton coupling at the attosecond-subnanometer scale: Tailoring strong light-matter interactions at room temperature
Knut and Alice Wallenberg Foundation (2019.0140), 2020-07-01 -- 2025-06-30.
Subject Categories (SSIF 2011)
Atom and Molecular Physics and Optics
Other Physics Topics
Condensed Matter Physics
DOI
10.1021/acsphotonics.3c01795