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
Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA.
Department of Physics, The University of Texas at Dallas, Richardson, TX, 75080, USA.
Nat Commun. 2020 Jun 19;11(1):3104. doi: 10.1038/s41467-020-16934-x.
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 as an intriguing playground to study phonon-exciton interactions and their interplay with charge, spin, and valley.
二维过渡金属二硫属化物中的强多体相互作用为研究不同准粒子之间的相互作用提供了一个独特的平台，例如显著的声子复制发射和修正的谷选择规则。预计大的面外磁场会通过将激子量子化为离散的朗道能级来改变激子 - 声子相互作用，而这在很大程度上尚未被探索。在这里，我们观察到源于声子 - 激子复合体的朗道能级，并在量子化磁场下直接探测激子 - 声子相互作用。声子 - 激子相互作用提升了暗三重态的朗道能级间跃迁选择规则，这表现为与亮三重态相比明显不同的朗道扇图案。这使我们能够通过实验提取空穴和电子的有效质量。朗道量子化的开始与谷塞曼位移的显著增加同时出现，表明对激子 - 声子相互作用有很强的多体效应。我们的工作证明单层WSe是研究声子 - 激子相互作用及其与电荷、自旋和谷的相互作用的一个有趣的平台。
