Pressure‐Induced Phase Transition in Weyl Semimetallic WTe2 |
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| Authors: | Juan Xia Dong‐Fei Li Jia‐Dong Zhou Peng Yu Jun‐Hao Lin Jer‐Lai Kuo Hai‐Bo Li Zheng Liu Jia‐Xu Yan Ze‐Xiang Shen |
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| Affiliation: | 1. Division of Physics and Applied Physics School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore;2. Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Normal University, Changchun, China;3. Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore;4. Materials Science and Technology Division, Oak Ridge National Lab, Oak Ridge, TN, USA;5. Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan;6. NOVITAS, Nanoelectronics Centre of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, Singapore;7. Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore, Singapore;8. Institute of Advanced Materials (IAM), Jiangsu National Synergistic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), Nanjing, P. R. China;9. CINTRA CNRS/NTU/THALES, UMI 3288, Research Techno Plaza, Singapore, Singapore |
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| Abstract: | Tungsten ditelluride (WTe2) is a semimetal with orthorhombic Td phase that possesses some unique properties such as Weyl semimetal states, pressure‐induced superconductivity, and giant magnetoresistance. Here, the high‐pressure properties of WTe2 single crystals are investigated by Raman microspectroscopy and ab initio calculations. WTe2 shows strong plane‐parallel/plane‐vertical vibrational anisotropy, stemming from its intrinsic Raman tensor. Under pressure, the Raman peaks at ≈120 cm?1 exhibit redshift, indicating structural instability of the orthorhombic Td phase. WTe2 undergoes a phase transition to a monoclinic T′ phase at 8 GPa, where the Weyl states vanish in the new T′ phase due to the presence of inversion symmetry. Such Td to T′ phase transition provides a feasible method to achieve Weyl state switching in a single material without doping. The new T′ phase also coincides with the appearance of superconductivity reported in the literature. |
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| Keywords: | first‐principles calculations high pressure phase transition Raman spectroscopy tungsten ditelluride |
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