Tuning relaxation and nonlinear upconversion of valley-exciton-polaritons in a monolayer semiconductor
Controlling exciton relaxation and energy conversion pathways via their coupling to photonic modes is a central task in cavity-mediated quantum materials research. In this context, the light-matter hybridization in optical cavities can lead to intriguing effects, such as modified carrier transport, enhancement of optical quantum yield, and control of chemical reaction pathways. Here, we investigate the impact of the strong light-matter coupling regime on energy conversion, both in relaxation and upconversion schemes, by utilizing a strongly charged MoSe<sub>2</sub> monolayer embedded in a spectrally tunable open-access cavity. We find that the charge carrier gas yields a significantly modified photoluminescence response of cavity exciton-polaritons, dominated by an intra-cavity like pump scheme. In addition, upconversion luminescence emerges from a population transfer from fermionic trions to bosonic exciton-polaritons. Due to the availability of multiple optical modes in the tunable open cavity, it seamlessly meets the cavity-enhanced double resonance condition required for an efficient upconversion. The latter can be actively tuned via the cavity length in-situ, displaying nonlinear scaling in intensity and fingerprints of the valley polarization. This suggests mechanisms that include both trion-trion Auger scattering and phonon absorption as its underlying microscopic origin.
Authors
- Martin Esmann (ORCID: https://orcid.org/0000-0002-2329-9696)
- Christian Schneider (ORCID: https://orcid.org/0000-0002-2268-471X)
- Sefaattin Tongay (ORCID: https://orcid.org/0000-0001-8294-984X)
- Takashi Taniguchi (ORCID: https://orcid.org/0000-0002-1467-3105)
- Kenji Watanabe (ORCID: https://orcid.org/0000-0003-3701-8119)
- Sven Höfling (ORCID: https://orcid.org/0000-0003-0034-4682)
- Ermin Malić (ORCID: https://orcid.org/0000-0003-1434-9003)
- Hangyong Shan (ORCID: https://orcid.org/0000-0003-3988-4870)
- Roberto Rosati (ORCID: https://orcid.org/0000-0002-2514-3425)
- Gilbert Leibeling
- Jamie M. Fitzgerald (ORCID: https://orcid.org/0000-0003-3652-0676)
- Falk Eilenberger (ORCID: https://orcid.org/0000-0002-4646-2484)
Institutions
- Carl von Ossietzky Universität Oldenburg (DE)
- Philipps University of Marburg (DE)
- National Institute for Materials Science (JP)
- University of Würzburg (DE)
- Fraunhofer Institute for Applied Optics and Precision Engineering (DE)
- Max Planck Institute for Chemical Ecology (DE)
- Max Planck Institute for the Science of Human History (DE)
- Arizona State University (US)
- Friedrich Schiller University Jena (DE)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-11-03
- DOI
- https://doi.org/10.1038/s41467-025-65737-5
- Primary Topic
- Strong Light-Matter Interactions
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- U.S. Department of Energy
- Deutsche Forschungsgemeinschaft
- Niedersächsisches Ministerium für Wissenschaft und Kultur
- Japan Society for the Promotion of Science
- Division of Chemical, Bioengineering, Environmental, and Transport Systems