Three-Dimensional Multiband d-p Model of Superconductivity in Spin-Chain Ladder Cuprate

We study the superconductivity in the three-dimensional multiband d-p model, in which a Cu${}_2$O${}_3$-ladder layer and a CuO${}_2$-chain layer are alternately stacked, as a model of the superconducting spin-chain ladder cuprate. $p_z$-Wave-like triplet superconductivity is found to be the most stable, and its dependence on interlayer coupling can explain the superconducting transition temperature dependence on pressure in real superconducting spin-chain ladder cuprates. The superconductivity may be enhanced if hole transfer from the chain layer to the ladder layer can be promoted beyond the typical transfer rate.