Precursor region with full phonon softening  above the charge-density-wave phase transition in 2h-tase$_2$

doi:doi:10.35097/1771

Precursor region with full phonon softening above the charge-density-wave phase transition in 2h-tase$_2$

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 TCDW, which is characterized by an overdamped phonon mode and not detectable in our photoemission experiments. Thus, 2H-TaSe2 exhibits structural before electronic static order and emphasizes the important lattice contribution to CDW transitions. Our ab-initio calculations explain the interplay of electron-phonon coupling and Fermi surface topology triggering the CDW phase transition and predict that the CDW soft phonon mode promotes emergent superconductivity near the pressure-driven CDW quantum critical point. TechnicalRemarks: data are stored in an project of origin lab format

BibTex:

@dataset{Weber_Frank_and_Shen_Xingchen_and_Heid_Rolf_and_Hott_Roland_and_Haghighirad_Amir-Abbas_and_Salzmann_Björn_and_Cantarino_Marli_dos_Reis_and_Monney_Claude_and_Said_Ayman_H_and_Frachet_Mehdi_and_Murphy_Bridget_and_Rossnagel_Kai_and_Rosenkranz_Stephan_2023,
    abstract = {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 TCDW, which is characterized by an overdamped phonon mode and not detectable in our photoemission experiments. Thus, 2H-TaSe2 exhibits structural before electronic static order and emphasizes the important lattice contribution to CDW transitions. Our ab-initio calculations explain the interplay of electron-phonon coupling and Fermi surface topology triggering the CDW phase transition and predict that the CDW soft phonon mode promotes emergent superconductivity near the pressure-driven CDW quantum critical point.
TechnicalRemarks: data are stored in an project of origin lab format},
    author = {Weber, Frank and Shen, Xingchen and Heid, Rolf and Hott, Roland and Haghighirad, Amir-Abbas and Salzmann, Björn and Cantarino, Marli dos Reis and Monney, Claude and Said, Ayman H. and Frachet, Mehdi and Murphy, Bridget and Rossnagel, Kai and Rosenkranz, Stephan},
    doi = {10.35097/1771},
    institution = {RADAR},
    title = {Precursor region with full phonon softening  above the charge-density-wave phase transition in 2h-tase$_2$},
    url = {https://service.tib.eu/ldmservice/vdataset/rdr-doi-10-35097-1771},
    year = {2023}
}