Phonon-exciton Interactions in WSe2 under a quantizing magnetic field

• Published in: Nature communications Vol. 11; no. 1; p. 3104
• Main Authors: Li, Zhipeng, Wang, Tianmeng, Miao, Shengnan, Li, Yunmei, Lu, Zhenguang, Jin, Chenhao, Lian, Zhen, Meng, Yuze, Blei, Mark, Taniguchi, Takashi, Watanabe, Kenji, Tongay, Sefaattin, Yao, Wang, Smirnov, Dmitry, Zhang, Chuanwei, Shi, Su-Fei
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 19.06.2020; Nature Publishing Group UK; Nature Portfolio
• Subjects: Chalcogenides; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Counting; Excitons; Fluorescence spectroscopy; Level (quantity); Lifts; Magnetic fields; Many body interactions; Monolayers; Phonons; Playgrounds; Trions; Two dimensional bodies; Two-dimensional materials; Valleys
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-16934-x

Abstract Strong many-body interaction in two-dimensional transitional metal dichalcogenides provides a unique platform to study the interplay between different quasiparticles, such as prominent phonon replica emission and modified valley-selection rules. A large out-of-plane magnetic field is expected to modify the exciton-phonon interactions by quantizing excitons into discrete Landau levels, which is largely unexplored. Here, we observe the Landau levels originating from phonon-exciton complexes and directly probe exciton-phonon interaction under a quantizing magnetic field. Phonon-exciton interaction lifts the inter-Landau-level transition selection rules for dark trions, manifested by a distinctively different Landau fan pattern compared to bright trions. This allows us to experimentally extract the effective mass of both holes and electrons. The onset of Landau quantization coincides with a significant increase of the valley-Zeeman shift, suggesting strong many-body effects on the phonon-exciton interaction. Our work demonstrates monolayer WSe 2 as an intriguing playground to study phonon-exciton interactions and their interplay with charge, spin, and valley.