Precursor region with full phonon softening above the charge-density-wave phase transition in 2H-TaSe₂.

ABSTRACT: Research on charge-density-wave (CDW) ordered transition-metal dichalcogenides continues to unravel new states of quantum matter correlated to the intertwined lattice and electronic degrees of freedom. Here, we report an inelastic x-ray scattering investigation of the lattice dynamics of the canonical CDW compound 2H-TaSe₂ complemented by angle-resolved photoemission spectroscopy and density functional perturbation theory. Our results rule out the formation of a central-peak without full phonon softening for the CDW transition in 2H-TaSe₂ and provide evidence for a novel precursor region above the CDW transition temperature T_CDW, which is characterized by an overdamped phonon mode and not detectable in our photoemission experiments. Thus, 2H-TaSe₂

SUBMITTER: Shen X 

PROVIDER: S-EPMC10638379 | biostudies-literature | 2023 Nov

REPOSITORIES: biostudies-literature