2003/04/24 by Carsten Honerkamp
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.68.104510
published as Phys. Rev. B 68, 104510 (2003) · 10 pages, 7 figures, submitted to Phys. Rev. B
arxiv created 2003/04/24 · openalex publication_date 2003/09/16 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Motivated by the recent finding of superconductivity in layered CoO2 compounds, we investigate superconducting and magnetic instabilities of interacting electrons on the two-dimensional triangular lattice. Using a one-loop renormalization-group scheme for weak- to moderate-coupling strengths, we find that for purely local interactions U>0 and small Fermi surfaces the renormalization-group flow remains bounded down to very low scales and no superconducting or other instabilities can be detected. Antiferromagnetic exchange interactions J generate a wide density region with a d_x2\ensuremath-y2+idxy\ensuremath-wave superconducting instability similar to recent proposals for the strongly correlated t\ensuremath-J model. For larger Fermi-surface volumes the interactions flow to strong coupling also for purely local interactions U>0. We find a singlet-pairing instability in the vicinity of strong magnetic ordering tendencies at three wave vectors for the Van Hove filling.