Interplay among critical temperature, hole content, and pressure in the cuprate superconductors.

Abstract

Within a BCS-type mean-field approach to the extended Hubbard model, a nontrivial dependence of ${T}_{c}$ on the hole content per unit Cu${\mathrm{O}}_{2}$ is recovered, in good agreement with the celebrated nonmonotonic universal behavior at normal pressure. Evaluation of ${T}_{c}$ at higher pressures is then made possible by the introduction of an explicit dependence of the tight-binding band and of the carrier concentration on pressure $P$. Comparison with the known experimental data for underdoped Bi2212 allows us to single out an "intrinsic" contribution to $\frac{d{T}_{c}}{\mathrm{dP}}$ from that due to the carrier concentration, and provides a remarkable estimate of the dependence of the intersite coupling strength on the lattice scale.