Year: 2025
Type: article
Abstract: Excitons dominate the optical response of two-dimensional (2D) semiconductors. Strong interactions produce peculiar excitonic complexes, which provide a testing ground for exciton and quantum many-body theories. Here, we report a hitherto unobserved many-body exciton that emerges upon filling both the K and Q valleys of WSe 2 . We optically probe the exciton landscape using charge-tunable devices with unusually thin dielectrics that facilitate doping up to several 10 13 cm −2 . We observe the emergence of the thermodynamically stable complex when 10 valleys are electrostatically filled. We gain insight into its physics using magneto-optical measurements. Our results are well-described by a model where the number of distinguishable Fermi seas interacting with the photoexcited electron-hole pair defines the complex’s behavior. In addition to expanding the repertoire of excitons in 2D semiconductors, this complex could probe the limit of exciton models and answer open questions about screened Coulomb interactions in 2D semiconductors.
Source: Nature Communications
Authors: Alain Dijkstra, Amine Ben Mhenni, Dinh Van Tuan, Elif Çetiner, Muriel Schur-Wilkens, Junghwan Kim, Laurin Steiner, Kenji Watanabe, Takashi Taniguchi, Matteo Barbone, Nathan P. Wilson, Hanan Dery, Jonathan J. Finley
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $6,990
Funders: U.S. Department of Energy, University of Rochester, International Max Planck Research School for Environmental, Cellular and Molecular Microbiology, European Commission, Deutsche Forschungsgemeinschaft, Ministry of Education, Culture, Sports, Science and Technology, International Max Planck Research School for Advanced Methods in Process and Systems Engineering, Munich Center for Quantum Science and Technology, International Max Planck Research School for Quantum Science and Technology, Japan Society for the Promotion of Science, Basic Energy Sciences, Division of Materials Sciences and Engineering
Awards: G1768993395, G2442584775, G258225891, G2586477669, G2632465609, G2960115771, G434337789, G4569868010, G4710139657, G4806815962, SPIN TRANSPORT IN GROUP IV MATERIALS AND 2D MEMBRANES, G5768859344, G6266672974, G6615889904, EXC 2111: Munich Center for Quantum Science and Technology (MCQST), Synthesis of high quality single crystals for sience of Boron Nitride
OpenAlex ID: W4415914868