2002/04/01 by Tetsuya Takimoto, Tôru Moriya, Toru Moriya
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Organic and Molecular Conductors Research #Physics of Superconductivity and Magnetism #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.66.134516
published as Phys. Rev. B 66, 134516 (2002) · 8 pages, 5 figures. submitted to PRB
arxiv created 2002/04/01 · openalex publication_date 2002/10/21 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The interplay between antiferromagnetism and superconductivity is studied by using the three-dimensional nearly half-filled Hubbard model with anisotropic transfer matrices tz and t_\ensuremath⊥. The phase diagrams are calculated for varying values of the ratio rz=tz/t_\ensuremath⊥ using the spin fluctuation theory within the fluctuation-exchange approximation. The antiferromagnetic phase around the half-filled electron density expands while the neighboring phase of the anisotropic d_x2\ensuremath-y2-wave superconductivity shrinks with increasing rz. For small rz Tc decreases slowly with increasing rz. For moderate values of rz we find a second order transition, with lowering temperature, from the d_x2\ensuremath-y2-wave superconducting phase to a phase where an incommensurate spin density wave (SDW) coexists with d_x2\ensuremath-y2-wave superconductivity. Resonance peaks discussed previously for two-dimensional (2D) superconductors are shown to survive in the d_x2\ensuremath-y2-wave superconducting phase of 3D systems. Soft components of the incommensurate SDW spin fluctuation mode grow as the coexistent phase is approached.