학술논문

Competition of disorder and electron-phonon coupling in 2H-TaSe$_{2-x}$S$_x$ ($0\le x\le 2$) as evidenced by Raman spectroscopy
Document Type
Working Paper
Source
Subject
Condensed Matter - Materials Science
Condensed Matter - Strongly Correlated Electrons
Condensed Matter - Superconductivity
Language
Abstract
The vibrational properties of 2H-TaSe$_{2-x}$S$_x$ ($0 \le x \le 2$) single crystals were probed using Raman spectroscopy and density functional theory calculations. The end members revealed two out of four symmetry-predicted Raman active modes, together with the pronounced two-phonon structure, attributable to the enhanced electron-phonon coupling. Additional peaks become observable due to crystallographic disorder for the doped samples. The evolution of the E$_{2g}^2$ mode Fano parameter reveals that the disorder has weak impact on electron-phonon coupling, which is also supported by the persistence of two-phonon structure in doped samples. As such, this research provides thorough insights into the lattice properties, the effects of crystallographic disorder on Raman spectra, and the interplay of this disorder with the electron-phonon coupling in 2H-TaSe$_{2-x}$S$_x$ compounds.