A mechanism leading to the spin-triplet superconductivity is proposed based on the antiferromagnetic spin fluctuation. The effects of anisotropy in spin fluctuation on the Cooper pairing and on the direction of d vector are examined in the one-band Hubbard model with RPA approximation. The gap equations for the anisotropic case are derived and applied to Sr_2RuO_4. It is found that a nesting property of the Fermi surface together with the anisotropy leads to the triplet superconductivity with the d=z(sin{k_x}\pm isin{k_y}), which is consistent with experiments.
@article{arxiv.cond-mat/0003296,
title = {Spin-triplet superconductivity due to antiferromagnetic spin-fluctuation in Sr_2RuO_4},
author = {Takeshi Kuwabara and Masao Ogata},
journal= {arXiv preprint arXiv:cond-mat/0003296},
year = {2009}
}