Determining the electron-phonon coupling in superconducting cuprates by resonant inelastic x-ray scattering: Methods and results on Nd1+xBa2-xCu3O7-delta

@article{ WOS:000603589200010,
Author = {Braicovich, Lucio and Rossi, Matteo and Fumagalli, Roberto and Peng,
   Yingying and Wang, Yan and Arpaia, Riccardo and Betto, Davide and De
   Luca, Gabriella M. and Di Castro, Daniele and Kummer, Kurt and Sala,
   Marco Moretti and Pagetti, Mattia and Balestrino, Giuseppe and Brookes,
   Nicholas B. and Salluzzo, Marco and Johnston, Steven and van den Brink,
   Jeroen and Ghiringhelli, Giacomo},
Title = {{Determining the electron-phonon coupling in superconducting cuprates by
   resonant inelastic x-ray scattering: Methods and results on
   Nd1+xBa2-xCu3O7-delta}},
Journal = {{PHYSICAL REVIEW RESEARCH}},
Year = {{2020}},
Volume = {{2}},
Number = {{2}},
Month = {{MAY 26}},
Abstract = {{The coupling between lattice vibration quanta and valence electrons can
   induce charge-density modulations and decisively influence the transport
   properties of materials, e.g., leading to conventional
   superconductivity. In high-critical-temperature superconductors, where
   electronic correlation is the main actor, the actual role of
   electron-phonon coupling (EPC) is being intensely debated theoretically
   and investigated experimentally. We present an in-depth study of how the
   EPC strength can be obtained directly from resonant inelastic x-ray
   scattering (RIXS) data through the theoretical approach derived by Ament
   et al. {[}Europhys. Lett. 95, 27008 (2011)]. The role of the model
   parameters (e.g., phonon energy omega(0), intermediate state lifetime
   1/Gamma, EPC matrix element M, and detuning energy Omega) is thoroughly
   analyzed, providing general relations among them that can be used to
   make quantitative estimates of the dimensionless EPC g = (M/omega(0))(2)
   without detailed microscopic modeling. We then apply these methods to
   very high-resolution Cu L-3-edge RIXS spectra of three
   Nd1+xBa2-xCu3O7-delta films. For the insulating antiferromagnetic parent
   compound, the value of M as a function of the in-plane momentum transfer
   is obtained for Cu-O bond-stretching (breathing) and bond-bending
   (buckling) phonon branches. For the underdoped and the nearly optimally
   doped samples, the effects of Coulomb screening and of
   charge-density-wave correlations on M are assessed. In light of the
   anticipated further improvements of the RIXS experimental resolution,
   this work provides a solid framework for an exhaustive investigation of
   the EPC in cuprates and other quantum materials.}},
DOI = {{10.1103/PhysRevResearch.2.023231}},
Article-Number = {{023231}},
EISSN = {{2643-1564}},
ResearcherID-Numbers = {{Rossi, Matteo/AAI-3879-2021
   Arpaia, Riccardo/Y-1247-2019
   Moretti, Marco/H-1034-2014}},
ORCID-Numbers = {{Rossi, Matteo/0000-0002-4254-0713
   Arpaia, Riccardo/0000-0003-4687-2376
   Moretti, Marco/0000-0002-9744-9976}},
Unique-ID = {{WOS:000603589200010}},
}