Raman-active modes of 1T′−WTe2 under tensile strain: A first-principles prediction

2019/02/12 by Wei Yang, Zi-Yang Yuan, Ziyang Yuan +11 · 1 citation
Chemistry · Engineering · Materials Science · Physics and Astronomy · #2D Materials and Applications #Anisotropy #Chemistry #Condensed matter physics #Crystallography #Perovskite Materials and Applications #Phonon #Physics #Quantum mechanics #Raman spectroscopy #Topological Materials and Phenomena #cond-mat.mes-hall #cond-mat.mtrl-sci

paper · pdf · doi:10.1103/physrevb.99.235401

published as Phys. Rev. B 99, 235401 (2019) · 13 pages, 5 figures

arxiv created 2019/02/12 · openalex created_date 2019/02/21 · openalex publication_date 2019/06/04 · arxiv updated 2019/06/12 · openalex updated_date 2026/08/05

Abstract

Monolayer 1T^\ensuremath'\ensuremath-WTe₂ attracts rapidly growing interests aiming for promising applications in spintronics, dissipationless transport, and quantum computations. Due to one-dimensional W-W chains, 1T^\ensuremath'\ensuremath-WTe₂ exhibits unique anisotropic structure and promising properties, which can be modified by simply applying strains. Based on first-principles calculations, we systematically study the phonon dispersion curves as well as the Raman-active modes of 1T^\ensuremath'\ensuremath-WTe₂ under different tensile strains. We find that one branch of acoustic phonon softens at special q points under a critical strain of \ensuremathε_a=11.55% along the a axis (with W\ensuremath-W chains) direction, or \ensuremathε_b=7.0% along the b-axis direction and \ensuremathε_ab=8.44% along the biaxial direction. Before reaching such critical strains, the Raman frequencies of A_g¹, A_g³, and A_g⁴ modes, contributing to the main peaks in Raman spectra of 1T^\ensuremath'\ensuremath-WTe₂, show anisotropic responses to different strains. The response to biaxial strains is found to be the most sensitive. We find that the frequency shift of A_g³ mode shows parabolic characters of strained 1T^\ensuremath'\ensuremath-WTe₂, then we split it into two parts and it shows a Raman-shift transition at \ensuremath∼5% strains. While for the\phantom\rule4pt0exA_g¹ and A_g⁴ modes, the frequencies change linearly.

Citations

• Failure Mechanisms of Graphene under Tension
• Generalized Gradient Approximation Made Simple
• Phonon and Raman scattering of two-dimensional transition metal dichalcogenides from monolayer, multilayer to bulk material
• The transition metal dichalcogenides discussion and interpretation of the observed optical, electrical and structural properties
• QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Observation of Coulomb gap in the quantum spin Hall candidate single-layer 1T’-WTe2

Cited by

• Achieving Large Uniaxial and Homogeneous Strain in Two-Dimensional Materials

Related

• Anomalous Lattice Dynamics of Mono-, Bi-, and Tri-layer WTe2
• A combined experimental and theoretical study of the electronic and vibrational properties of bulk and few-layer Td-WTe2
• Raman fingerprint of semi-metal WTe2 from bulk to monolayer
• Observation of low-frequency Raman peak in layered WTe₂
• Anisotropic Phonon Transport, Thermal Expansion and Thermomechanics in Monolayer Td-WTe2