Effect of nonuniform hole-content distribution within the interlayer pair-tunneling mechanism of layered HTSC

摘要

The interlayer pair-tunneling (ILPT) mechanism for high-T_c superconductivity predicts the dependence of the (optimal) critical temperature T_c on the number of layers n within a homologous series of layered cuprate oxides. We generalize the mean-field procedure employed to evaluate T_c within an extended in-plane Hubbard model in the presence of ILPT, developed for a bilayer complex (n = 2), to the case of n = 3,4 inequivalent superconducting layers. As a function of doping, we show how a nonuniform hole-content distribution among different layers affects T_c. In particular, depending on doping, the onset of superconductivity may be ruled by inner or outer layers. The latter result may be related to recent experimental data of T_c as a function of pressure in Tl-and Bi-based layered superconductors.