| Summary: | We investigate the connection between the local electron correlation and the momentum dependence of the spin susceptibility and the superconducting gap functions in Sr_{2}RuO_{4} using density-functional theory combined with dynamical mean-field theory. Adopting a frequency-dependent two-particle vertex moves the zero-energy spin susceptibility peaks towards the Brillouin zone center, compared with the random-phase approximation, which basically retains the peak positions closer to the Brillouin zone boundary as determined by the Fermi-surface nesting. We find that the d_{xy} orbital plays a central role here via its enhanced correlation strength. Solving the linearized Eliashberg equation from this spin susceptibility, the prime candidates for the superconducting gap are an s-wave and a nearly degenerate d-wave solutions, all in the spin singlet. Furthermore, another set of degenerate spin-singlet gap functions emerges, odd with respect to the k point as well as orbital exchanges. We show that the stability of these gap functions is strongly dependent on the peak position of the spin susceptibility in the Brillouin zone.
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