Spin-fluctuation-mediated pairing symmetry on the metallic kagome lattice.

We study the magnetic properties and the superconducting pairing mediated by spin fluctuations on the metallic kagome lattice by using the Hubbard model and the fluctuation exchange approximation. It is found that the spin susceptibility is caused by the nesting of the renormalized Fermi surface. We point out that superconductivity will be favored in the spin-singlet channel and may be more easily realized around 25% hole doping. We find an evolution of the pairing state from a d-wave-like symmetry, described by the E(2g) representation of the group D(6h) at low dopings, to that described by the A(2g) representation at heavy hole dopings.