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Pressure‐Induced Phase Transition in Weyl Semimetallic WTe 2
Author(s) -
Xia Juan,
Li DongFei,
Zhou JiaDong,
Yu Peng,
Lin JunHao,
Kuo JerLai,
Li HaiBo,
Liu Zheng,
Yan JiaXu,
Shen ZeXiang
Publication year - 2017
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201701887
Subject(s) - weyl semimetal , raman spectroscopy , condensed matter physics , materials science , orthorhombic crystal system , superconductivity , monoclinic crystal system , phase transition , anisotropy , magnetoresistance , phase (matter) , semimetal , physics , crystal structure , chemistry , crystallography , optics , band gap , quantum mechanics , magnetic field
Tungsten ditelluride (WTe 2 ) is a semimetal with orthorhombic T d phase that possesses some unique properties such as Weyl semimetal states, pressure‐induced superconductivity, and giant magnetoresistance. Here, the high‐pressure properties of WTe 2 single crystals are investigated by Raman microspectroscopy and ab initio calculations. WTe 2 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 T d phase. WTe 2 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 T d 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.