%0 Journal Article
%A Diego, Josu
%A Subires, D.
%A Said, Ayman
%A Chaney, D. A.
%A Korshunov, Artem
%A Garbarino, G.
%A Diekmann, F.
%A Mahatha, S. K.
%A Pardo, V.
%A Wilkinson, J. M.
%A Lord, J. S.
%A Strempfer, Joerg
%A Bereciartua Perez, Pablo Javier
%A Francoual, Sonia
%A Popescu, C.
%A Tallarida, M.
%A Dai, J.
%A Bianco, Raffaello
%A Monacelli, Lorenzo
%A Calandra, Matteo
%A BOSAK, Alexei
%A Mauri, Francesco
%A Rossnagel, Kai
%A Fumega, Adolfo O.
%A Errea, Ion
%A Blanco-Canosa, Santiago
%T Electronic structure and lattice dynamics of 1 T − VSe<sub>2</sub> : Origin of the three-dimensional charge density wave
%J Physical review / B
%V 109
%N 3
%@ 2469-9950
%C Woodbury, NY
%I Inst.
%M PUBDB-2024-00348
%P 035133
%D 2024
%X To characterize in detail the charge density wave (CDW) transition of 1 T − VSe<sub>2</sub>, its electronic structure and lattice dynamics are comprehensively studied by means of x-ray diffraction, muon spectroscopy, angle resolved photoemission (ARPES), diffuse and inelastic x-ray scattering, and state-of-the-art first-principles density functional theory calculations. Resonant elastic x-ray scattering does not show any resonant enhancement at either V or Se, indicating that the CDW peak at the K edges describes a purely structural modulation of the electronic ordering. ARPES experiments identify (i) a pseudogap at T > T<sub>CDW</sub>, which leads to a depletion of the density of states in the ML-M'L' plane at T > T<sub>CDW</sub>, and (ii) anomalies in the electronic dispersion reflecting a sizable impact of phonons on it. A diffuse scattering precursor, characteristic of soft phonons, is observed at room temperature (RT) and leads to the full collapse of the low-energy phonon (ω<sub>1</sub>) with propagation vector (0.25 0 −0.3) r.l.u. We show that the frequency and linewidth of this mode are anisotropic in momentum space, reflecting the momentum dependence of the electron-phonon interaction (EPI), hence demonstrating that the origin of the CDW is, to a much larger extent, due to the momentum dependent EPI with a small contribution from nesting. The pressure dependence of the ω<sub>1</sub> soft mode remains nearly constant up to 13 GPa at RT, with only a modest softening before the transition to the high-pressure monoclinic C2/m phase. The wide set of experimental data is well captured by our state-of-the art first-principles anharmonic calculations with the inclusion of van der Waals corrections in the exchange-correlation functional. The comprehensive description of the electronic and dynamical properties of VSe<sub>2</sub> reported here adds important pieces of information to the understanding of the electronic modulations in the family of transition-metal dichalcogenides. 
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:001174196600011
%R 10.1103/PhysRevB.109.035133
%U https://bib-pubdb1.desy.de/record/601655