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DOE OSTI · 1647005

Phonon-exciton Interactions in WSe 2 under a quantizing magnetic field

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
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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.

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71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICSFluorescence spectroscopyTwo-dimensional materials

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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. 2020-06-19. Phonon-exciton Interactions in WSe 2 under a quantizing magnetic field. https://doi.org/10.1038/s41467-020-16934-x

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