2003/12/31 by Seiichiro Onari, Ryotaro Arita, Kazuhiko Kuroki +1 · 3 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Organic and Molecular Conductors Research #Physics of Superconductivity and Magnetism #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.70.094523
published as PRB, 70, 094523 (2004) · 6 pages, 8 figures
openalex publication_date 2004/09/30 · arxiv created 2004/10/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/03
In order to explore how superconductivity arises when charge fluctuations and spin fluctuations coexist, we have obtained a phase diagram against the off-site repulsion V and band filling n for the extended, repulsive Hubbard model on the square lattice with the fluctuation exchange approximation. We have found the existence of (i) a transition between dxy and d_x2\ensuremath-y2 pairing symmetries, (ii) f-pairing in between the d_x2\ensuremath-y2 and CDW phases for intermediate 0.5<n<1.0 and large V, and (iii) for anisotropic cases the pairing symmetry changing, in agreement with a previously proposed ``generic phase diagram,'' as d\ensuremath→f\ensuremath→s when V (hence the charge fluctuations) are increased. All these are consequences of the structure in the charge and spin susceptibilities, which have peaks habitating at common or segregated positions in k space.