Investigation of the Electron-Phonon Coupling in Dirac Semimetal PdTe2 via Temperature-Dependent Raman Spectroscopy

Layered Palladium ditelluride (PdTe2) is an interesting noble-transition-metal dichalcogenide with high electrical and thermal conductivity, exhibiting superconductivity and a type-II Dirac semimetallic phase due to the increased electron-phonon (e-ph) coupling. Herein, the e-ph coupling constant lambda of E (g) (in-plane) and A (1g) (out-of-plane) modes in the exfoliated PdTe2 nanoflakes via temperature-dependent Raman spectroscopy within the temperature range from 80 to 580 K is determined. Both E (g) mode with a Gaussian line shape and A (1g) mode with a Breit-Wigner-Fano line shape show nonlinear frequency redshift and linewidth broadening with temperature. The extracted e-ph coupling constants are lambda E g = 1.54 and lambda A 1 g = 0.55, respectively. The Raman results confirm that PdTe2 is a phonon-mediated Bardeen-Cooper-Schrieffer superconductor.