Determining the electron-phonon coupling in superconducting cuprates by resonant inelastic x-ray scattering: Methods and results on Nd1+xBa2-xCu3O7-δ
Artikel i vetenskaplig tidskrift, 2020
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 ω0, intermediate state lifetime 1/Γ, EPC matrix element M, and detuning energy Ω) is thoroughly analyzed, providing general relations among them that can be used to make quantitative estimates of the dimensionless EPC g=(M/ω0)2 without detailed microscopic modeling. We then apply these methods to very high-resolution Cu L3-edge RIXS spectra of three Nd1+xBa2−xCu3O7−δ 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.
Författare
Lucio Braicovich
European Synchrotron Radiation Facility (ESRF)
Politecnico di Milano
Matteo Rossi
Politecnico di Milano
Roberto Fumagalli
Politecnico di Milano
Y. Y. Peng
Politecnico di Milano
Yan Wang
University of Tennessee
Riccardo Arpaia
Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik
Davide Betto
European Synchrotron Radiation Facility (ESRF)
Gabriella M. De Luca
Universita degli Studi di Napoli Federico II
CNR SPIN Institute - Napoli
D. Di Castro
Universita degli Studi di Roma Tor Vergata
Kurt Kummer
European Synchrotron Radiation Facility (ESRF)
Marco Moretti Sala
Politecnico di Milano
Mattia Pagetti
Politecnico di Milano
G Balestrino
Universita degli Studi di Roma Tor Vergata
Nicholas B. Brookes
European Synchrotron Radiation Facility (ESRF)
Marco Salluzzo
CNR SPIN Institute - Napoli
S. Johnston
Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden
University of Tennessee
J. van den Brink
Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden
Washington University in St. Louis
Technische Universität Dresden
Giacomo Ghiringhelli
Politecnico di Milano
Physical Review Research
26431564 (ISSN)
Vol. 2 2 023231Utvecklingen av nano laddning ordning i supraledande YBCO nanostrukturer
Vetenskapsrådet (VR) (2017-00382), 2017-07-01 -- 2020-06-30.
Ämneskategorier
Den kondenserade materiens fysik
DOI
10.1103/PhysRevResearch.2.023231