Interplay between electron-phonon and electron-electron interactions

O. Rösch, J. E. Han, O. Gunnarsson, Vincent Henry Crespi

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

We discuss the interplay between electron-electron and electron-phonon interactions for alkali-doped fullerides and high temperature superconductors. Due to the similarity of the electron and phonon energy scales, retardation effects are small for fullerides. This raises questions about the origin of superconductivity, since retardation effects are believed to be crucial for reducing effects of the Coulomb repulsion in conventional superconductors. We demonstrate that by treating the electron-electron and electron-phonon interactions on an equal footing, superconductivity can be understood in terms of a local pairing. The Jahn-Teller character of the important phonons in fullerides plays a crucial role for this result. To describe effects of phonons in cuprates, we derive a t-J model with phonons from the three-band model. Using exact diagonalization for small clusters, we find that the anomalous softening of the half-breathing phonon as well as its doping dependence can be explained. By comparing the solution of the t-J model with the Hartree-Fock approximation for the three-band model, we address results obtained in the local-density approximation for cuprates. We find that genuine many-body results, due to the interplay between the electron-electron and electron-phonon interactions, play an important role for the the results in the t-J model.

Original languageEnglish (US)
Pages (from-to)118-132
Number of pages15
JournalPhysica Status Solidi (B) Basic Research
Volume242
Issue number1
DOIs
StatePublished - Jan 1 2005

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Electron-electron interactions
electron scattering
fullerides
Electrons
Electron-phonon interactions
electron phonon interactions
Phonons
phonons
electrons
cuprates
Superconductivity
superconductivity
scale effect
Hartree approximation
Local density approximation
breathing
High temperature superconductors
high temperature superconductors
softening
Alkalies

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Rösch, O. ; Han, J. E. ; Gunnarsson, O. ; Crespi, Vincent Henry. / Interplay between electron-phonon and electron-electron interactions. In: Physica Status Solidi (B) Basic Research. 2005 ; Vol. 242, No. 1. pp. 118-132.
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Interplay between electron-phonon and electron-electron interactions. / Rösch, O.; Han, J. E.; Gunnarsson, O.; Crespi, Vincent Henry.

In: Physica Status Solidi (B) Basic Research, Vol. 242, No. 1, 01.01.2005, p. 118-132.

Research output: Contribution to journalArticle

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