The optical evidence of atomic reconstruction in twisted bilayer MoS<sub>2</sub>
ORAL
Abstract
In two-dimensional materials, Moiré superlattices formed by stacking two monolayers with lattice constant mismatch or rotational misalignment have been widely used to manipulate their electronic and optical properties. Here, we employ low-frequency Raman measurements and DFT calculations to demonstrate atomic reconstruction in the MoS2 homobilayer with a small twist angle (θ). For 0°＜θ≤3.5°, only interlayer Raman mode of 3R stacking with stable peak position is presented, indicating the overwhelming expansion of stable stacking in small twist angle due to structural relaxation. For 3.5°＜θ≤6°, the small Moiré supercell with weak relaxation results in mixed in-plane and out-of-plane vibrations. The shear mode quickly disappears with an increasing twist angle, while mixed breathing modes are observed. Our work provides a novel strategy to understand and monitor the evolution of structural relaxation in moiré superlattices in two-dimensional van der Waals materials.
*Funding from DOE and a catalyst grant provided by the College of Natural Science at the University of Texas-Austin are gratefully acknowledged.
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Presenters
Jiamin Quan
Physics, University of Texas at Austin
Department of Physics, The University of Texas at Austin
University of Texas at Austin
Department of Physics, Complex Quantum Systems, and Texas Materials Institutes, University of Texas at Austin
Authors
Jiamin Quan
Physics, University of Texas at Austin
Department of Physics, The University of Texas at Austin
University of Texas at Austin
Department of Physics, Complex Quantum Systems, and Texas Materials Institutes, University of Texas at Austin
Lukas Linhart
Vienna University of Technology
Miao-Ling Lin
Chinese Academy of Sciences
State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors,Chinese Academy of Sciences, Beijing 100083, China
Chun Yuan Wang
Physics, University of Texas at Austin
University of Texas at Austin
Wei-Ting Hsu
Department of Physics, The University of Texas at Austin
University of Texas at Austin
Junho Choi
Physics, University of Texas at Austin
University of Texas at Austin
Department of Physics, Complex Quantum Systems, and Texas Materials Institutes, University of Texas at Austin
Carter Young
Department of Physics, University of Texas at Austin
University of Texas at Austin
Department of Physics, Complex Quantum Systems, and Texas Materials Institutes, University of Texas at Austin
Takashi Taniguchi
National Institute for Materials Science
National Institute for Material Science, Japan
National Institute of Material Science in Tsukuba
Kyoto Univ
Chemical Engineering, Kyoto University
Advanced Materials Laboratory, National Institute for Materials Science
National Institute of Materials Science (NIMS)
National Institute of Materials Science, Japan
Kyoto University
Chih-Kang Shih
University of Texas at Austin
Physics, University of Texas at Austin
Department of Physics, The University of Texas at Austin
Allan MacDonald
University of Texas at Austin
Physics, University of Texas at Austin
Department of Physics, University of Texas at Austin
Department of Physics, The University of Texas at Austin
Ping-Heng Tan
Chinese Academy of Sciences
State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors,Chinese Academy of Sciences, Beijing 100083, China
State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences
Florian M Libisch
Vienna University of Technology
Xiaoqin (Elaine) Li
Physics, University of Texas at Austin
Department of Physics, The University of Texas at Austin
Department of Physics, University of Texas at Austin
University of Texas at Austin
Department of Physics, Complex Quantum Systems, and Texas Materials Institutes, University of Texas at Austin
