Variation of the superconducting transition temperature of hole-doped copper oxides

The experimentally observed difference of the superconducting critical temperature T-c of hole-doped cuprates is studied by using an extended interlayer coupling model for layered d-wave superconductors. We show that the change of the maximum T-c from series to series is determined by the next-nearest-neighboring hopping t('), while the difference of the maximum T-c among the compounds in a homogeneous series is controlled by the interlayer pairing strength. Our results also provide helpful guidelines in the search for new high-T-c superconductors.