D-wave overlapping band model for cuprate superconductors

TL;DR

This paper proposes a multiband d-wave superconducting model incorporating band overlapping and Fermi surface topology changes to explain experimental critical temperature and gap data in cuprate superconductors.

Contribution

It introduces a novel multiband model with band overlapping and d-wave symmetry within the BCS framework for cuprates.

Findings

Numerical estimates of coupling and band overlap parameters as functions of doping.

Agreement with experimental $T_c(x)$ and $\Delta_0(x)$ data for La2-xSrxCuO4.

Insight into the role of band structure in high-temperature superconductivity.

Abstract

Within the BCS framework a multiband model with d-wave symmetry is considered. Generalized Fermi surface topologies via band overlapping are introduced. The band overlap scale is of the order of the Debye energy. The order parameters and the pairing have d-wave symmetry. Experimental values reported for the critical temperatures $T_c(x)$ and the order parameters, $\Delta_0(x)$, in terms of dopping $x$ are used. Numerical results for the coupling and the band overlapping parameters in terms of the doping are obtained for the cuprate superconductor $La_{2-x}Sr_xCuO_4$.