Valley-Controlled Many-Body Exciton Interactions in Monolayer WSe <sub>2</sub> Phototransistors
via valley-selective excitation using polarization-resolved pulsed-laser photocurrent spectroscopy. Circular excitation selectively populates excitons in a single valley, whereas linear excitation populates both valleys, inducing a valley-dependent nonlinear photoresponse. We observe helicity-dependent exciton renormalization, alongside a 2-fold enhancement of sublinear photocurrent scaling under circular excitation, reflecting a single-valley population of interacting excitons. A microscopic model incorporating intervalley-exchange and exciton-exciton annihilation mediated by dark and bright exciton populations reproduces the nonlinear valley-selective response. These results establish the valley degree of freedom as an all-optical control parameter for tuning many-body excitonic effects and exploring correlated exciton states and valleytronic applications in two-dimensional semiconductors.
Authors
- Daniel Vaquero (ORCID: https://orcid.org/0000-0001-7025-125X)
- Ermin Malić (ORCID: https://orcid.org/0000-0003-1434-9003)
- Cédric A. Cordero‐Silis (ORCID: https://orcid.org/0000-0002-0842-3169)
- Roberto Rosati (ORCID: https://orcid.org/0000-0002-2514-3425)
- Daniel Erkensten (ORCID: https://orcid.org/0000-0002-9632-6376)
- Kenji Watanabe
- Takashi Taniguchi
- Martijn H Takens
- Marcos H D Guimarães
Institutions
- Philipps University of Marburg (DE)
- University of Groningen (NL)
- National Institute for Materials Science (JP)
Publication Details
- Journal
- Nano Letters
- Published
- 2026-04-30
- DOI
- https://doi.org/10.1021/acs.nanolett.6c01091
- Primary Topic
- 2D Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Deutsche Forschungsgemeinschaft
- Ministry of Education, Culture, Sports, Science and Technology
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek
- Japan Society for the Promotion of Science
- Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen
- Core Research for Evolutional Science and Technology
- HORIZON EUROPE European Research Council