Pressure-induced creation and annihilation of Weyl points in Td- and 1T"-Mo0.5W0.5Te2

Abstract

By means of first-principles density-functional theory calculations, we investigate the role of hydrostatic pressure on the electronic structure of Td (Pmn21 ) and 1T" (Pm) phases of Weyl semimetal Mo0.5 W0.5 Te2 , which is a promising material for phase-change memory technology and superconductivity. We particularly focus on changes occurring in the distribution of the gapless Weyl points (WPs) within 0 to 45 GPa pressure range. We further investigate the structural phase transition and lattice dynamics of the Td and 1T" phases within the aforementioned pressure range. Our calculations suggest that both the Td and 1T" phases of Mo0.5 W0.5 Te2 host four WPs in their full Brillouin zone at zero pressure. The total number of WPs increases to 44 (36) with increasing pressure via pair creation up to 20 (15) GPa for the T d (1T 00 ) phase, and beyond this pressure pair annihilation of WPs starts occurring leaving only 16 WPs at 45 GPa in both phases. The enthalpy versus pressure data reveal that the 1T 00 phase is more favorable below the critical pressure of 7.5 GPa, however, beyond this critical pressure the Td phase becomes enthalpically favorable. We also provide the calculated x-ray diffraction spectra along with the calculated Raman- and infrared-active phonon frequencies to facilitate the experimental identification of the studied phases.

10 pages, 5 figures

References in corpus (22)

• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Quantum Spin Hall Effect and Topological Field Effect Transistor in Two-Dimensional Transition Metal Dichalcogenides
• Phase transition between the quantum spin Hall and insulator phases in 3D: emergence of a topological gapless phase
• Discovery of Weyl fermion semimetals and topological Fermi arc states
• Weyl Semimetals, Fermi Arcs and Chiral Anomalies (A Short Review)
• Discovery of a new type of topological Weyl fermion semimetal state in Mo${}_x$W${}_{1-x}$Te${}_2$
• MechElastic: A Python Library for Analysis of Mechanical and Elastic Properties of Bulk and 2D Materials
• Engineering the structural and electronic phases of MoTe2 through W substitution
• Review of experiments on the chiral anomaly in Dirac-Weyl semimetals
• The extremely large magnetoresistance in the Candidate Type-II Weyl semimetal MoTe2
• Time-reversal invariant topological superconductivity in doped Weyl semimetals
• Experimental observation of anisotropic Adler-Bell-Jackiw anomaly in type-II Weyl semimetal WTe${}_{1.98}$ crystals at the quasi-classical regime
• Photogalvanic effect in Weyl semimetals
• Anticorrelation between polar lattice instability and superconductivity in the Weyl semimetal candidate MoTe2
• MoTe2 : An uncompensated semimetal with extremely large magnetoresistance
• The origin of the turn-on phenomenon in Td-MoTe2
• Topology of Triple-Point Metals
• Observation of spin-polarized bands and domain-dependent Fermi arcs in polar Weyl semimetal MoTe${}_2$
• Superconducting properties of MoTe${}_2$ from the $abinitio$ anisotropic Migdal-Eliashberg theory
• Evolution of the structural transition in Mo${}_{1-x}$W${}_x$Te${}_2$
• Dimensionality-dependent type-II Weyl semimetal state in Mo${}_{0.25}$W${}_{0.75}$Te${}_2$

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