ENHANCEMENT OF SUPERCONDUCTING CORRELATION DUE TO INTERLAYER TUNNELING

Interlayer single-particle tunneling between the Cu-O layers suppresses the in-plane short-range magnetic order (which is modeled as spin density wave (SDW) insulator). Doping over the SDW state kills perfect nesting of the Fermi surface (FS) in certain directions and hence the SDW gap reduces to zero in those directions of the FS. Coupling between the planes through interlayer tunneling (t(perpendicular to)) further suppresses the in-plane magnetic SDW gap. Superconductivity arises in the gapless regions of the FS under the ''modified spin-bag'' mechanism. We show that the highest T-c can only be obtained for non-zero t(perpendicular to) based on this mechanism.