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Journal articles
$\eta$ collective mode as A$_{1g}$ Raman resonance in cuprate superconductors
Abstract : We discuss the possible existence a spin singlet excitation with charge ±2 (η-mode) originating the A 1g Raman resonance in cuprate superconductors. This η-mode relates the d-wave superconducting singlet pairing channel to a d-wave charge channel. We show that the η boson forms a particle-particle bound state below the 2∆ threshold of the particle-hole continuum where ∆ is the maximum d-wave gap. Within a generalized random phase approximation and Bethe-Salpether approximation study, we find that this mode has energies similar to the resonance observed by Inelastic Neutron Scattering (INS) below the superconducting (SC) coherent peak at 2∆ in various SC cuprates compounds. We show that it is a very good candidate for the resonance observed in Raman scattering below the 2∆ peak in the A 1g symmetry. Since the η-mode sits in the S = 0 channel, it may be observable via Raman, X-ray or Electron Energy Loss Spectroscopy probes.
Cited literature [42 references]
https://hal-cea.archives-ouvertes.fr/cea-01469552
Contributor : Emmanuelle de Laborderie <>
Submitted on : Thursday, February 16, 2017 - 3:24:30 PM
Last modification on : Wednesday, April 14, 2021 - 12:12:48 PM
Long-term archiving on: : Wednesday, May 17, 2017 - 7:42:03 PM
Contributor : Emmanuelle de Laborderie <>
Submitted on : Thursday, February 16, 2017 - 3:24:30 PM
Last modification on : Wednesday, April 14, 2021 - 12:12:48 PM
Long-term archiving on: : Wednesday, May 17, 2017 - 7:42:03 PM
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1504.03951.pdf
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