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

Politecnico di Milano

European Synchrotron Radiation Facility (ESRF)

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 (MC2), 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

University of Tennessee

Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden

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

2643-1564 (eISSN)

Vol. 2 023231

Utvecklingen av nano laddning ordning i supraledande YBCO nanostrukturer

Vetenskapsrådet (VR), 2017-07-01 -- 2020-06-30.

Ämneskategorier

Den kondenserade materiens fysik

DOI

10.1103/PhysRevResearch.2.023231

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Senast uppdaterat

2020-11-26