Triplet Pairing Superconductivity Induced by Short-Range Ferromagnetic Correlations in Sr${}_2$RuO${}_4$

Abstract

The microscopic origin of triplet superconductivity in Sr${}_2$RuO${}_4$ is discussed, paying attention to the role of Coulomb interaction, $U_{pp}$, at the O site. It is shown on the $d$-$p$ model that $U_{pp}$ induces a ferromagnetic exchange interaction between "d-electrons" (molecular orbital with $d_{xy}$-symmetry) at adjacent Ru sites, leading to short-range ferromagnetic correlations and promoting Cooper pairing with ($\sin p_x\pm\ii\sin p_y$)-symmetry on the $\gamma$-band. The reason why such ferromagnetic correlations work effectively may be traced back to the fact that the level of 4d-electrons at Ru sites is relatively low and located near that of $2p$-electrons at O sites.

9 pages, 6 figures, to be published in J. Phys. Soc. Jpn

References in corpus (5)

• Gap Structure of the Spin-Triplet Superconductor Sr2RuO4 Determined from the Field-Orientation Dependence of Specific Heat
• Interband proximity effect and nodes of superconducting gap in Sr2RuO4
• Orbital Fluctuation-Induced Triplet Superconductivity : Mechanism of Superconductivity in ${\mathrm{Sr}}_2{\mathrm{RuO}}_4$
• Off-site-repulsion induced Triplet Superconductivity: a possibility of chiral p${}_{x+y}$ pairing in Sr${}_2$RuO${}_4$
• Quantum Monte Carlo study of the pairing symmetry competition in the Hubbard model

Cited by in corpus (6)

• Evaluation of Spin-Triplet Superconductivity in Sr2RuO4
• Spin-triplet superconductivity in Sr2RuO4 due to orbital and spin fluctuations: Analyses by two-dimensional renormalization group theory and self-consistent vertex-correction method
• Spin Triplet Superconductivity in Sr2RuO4 due to Orbital and Spin Fluctuations: Analysis by Two-Dimensional Renormalization Group Theory
• Spin-orbit Coupling and Multiple Phases in Spin-triplet Superconductor Sr${}_2$RuO${}_4$
• Effect of Spin-Orbit Interaction in Spin-Triplet Superconductor: Structure of $\mathbf{d}$-vector and Anomalous ${}^{17}$O-NQR Relaxation in Sr${}_2$RuO${}_4$
• Intrinsic Angular Momentum and Intrinsic Magnetic Moment of Chiral Superconductor on Two-Dimensional Square Lattice