Coupling to zone-center optical phonons in VSe2 enhanced by charge density waves

DOI: 10.1103/PhysRevB.104.235137

Authors: Y. Falke (Universität zu Köln) , N. Ehlen (Universität zu Köln) , G. Marini (University of L'Aquila) , A. V. Fedorov (Universität zu Köln; Leibniz IFW-Dresden; Helmholtz-Zentrum Berlin für Materialien und Energie) , V. Y. Voroshnin (Leibniz IFW-Dresden; Helmholtz-Zentrum Berlin für Materialien und Energie) , B. V. Senkovskiy (Universität zu Köln) , K. Nikonov (Universität zu Köln; Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences) , M. Hoesch (Diamond Light Source; Deutsches Elektronen-Synchrotron) , T. K. Kim (Diamond Light Source) , L. Petaccia (Elettra Sincrotrone Trieste) , G. Di Santo (Elettra Sincrotrone Trieste) , T. Szkopek (McGill University) , G. Profeta (University of L'Aquila) , A. Gruneis (Universität zu Köln)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review B , VOL 104

State: Published (Approved)
Published: December 2021
Diamond Proposal Number(s): 17064

Abstract: We investigate electron-phonon coupling (EPC) in the charge density wave (CDW) phase of V Se 2 by Raman spectroscopy, angle-resolved photoemission spectroscopy (ARPES), and ab initio calculations. Zone folding induced by the 4 × 4 in-plane CDW phase promotes the appearance of a Raman peak at ∼ 170 cm − 1 . The suppression of ARPES intensity in parts of the Fermi surface is also a result of CDW-induced zone folding and anticrossing of the electron energy bands. The appearance of the new Raman peak is in line with the ARPES observation of a kink feature in the spectral function at the same energy. A self-energy analysis yields an EPC constant of λ = 0.3 . Our calculations of the EPC are in excellent agreement and reveal that the kink is caused by several optical phonon branches close in energy. Our paper highlights the CDW phase as a means of inducing EPC pathways to optical phonons that directly affect its Raman spectrum.

Journal Keywords: Charge density waves; Fermi surface; First-principles calculations

Subject Areas: Physics, Materials


Instruments: I05-ARPES

Other Facilities: Elettra

Added On: 23/12/2021 07:39

Discipline Tags:

Superconductors Quantum Materials Physics Hard condensed matter - structures Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)