Phase diagram of the two-dimensional extended Hubbard model: Pairing from charge and spin fluctuations

Seiichiro Onari, Ryotaro Arita, Kazuhiko Kuroki, Hideo Aoki

Research output: Contribution to journalArticle

Abstract

We study theoretically the symmetry of pairing when charge and spin fluctuations coexist to mediate the pairing for the extended Hubbard model on the square lattice, where the off-site repulsion V controls the charge fluctuation. Phase diagram is obtained, with the fluctuation exchange approximation, on the plane of V and the band filling n (quarter to half filling), which reveals: (i) a transition between dxy and dx2-y2 pairing symmetries for a weaker V, (ii) f-pairing in between the dx2-y2 and CDW phases for a stronger V, and (iii) for an anisotropic (quasi-1D) case the pairing symmetry changed, in agreement with a previously proposed "generic phase diagram" (Phys. Rev. B 63 (2001) 094509), as d→f→s with V. All these are consequences of the structure in the charge and spin susceptibilities which have peaks habitating at common or segregated positions, depending on V and n, in k space.

Original languageEnglish
Pages (from-to)518-520
Number of pages3
JournalPhysica B: Condensed Matter
Volume359-361
Issue numberSPEC. ISS.
DOIs
Publication statusPublished - Apr 30 2005

Keywords

  • Extended Hubbard model
  • Superconductivity

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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