Spin-triplet superconductivity induced by off-site Coulomb interaction in a triangular lattice

In order to study how superconductivity emerges when the charge fluctuation coexists with the spin fluctuation in a triangular lattice, we obtain a phase diagram against the nearest-neighbor Coulomb repulsion V and band filling n on the extended Hubbard model using the fluctuation exchange (FLEX) approximation. We find that a charge density wave (CDW) phase exists in the region where the value of V is large, and the f-wave spin-triplet pairing mediated by a strong charge fluctuation is dominant near the CDW phase.