Strong Coupling Approach to the d-p Model on the Basis of Fermi Liquid Theory

TL;DR

This paper investigates the superconducting transition temperature in a bilayer d-p model using a strong coupling approach based on Fermi liquid theory, revealing suppression of Tc and its proportionality to Fermi energy in the strong coupling regime.

Contribution

It introduces a strong coupling analysis of the bilayer d-p model using Fermi liquid theory, highlighting differences from traditional methods and reproducing key features of underdoped superconductors.

Findings

Tc is suppressed in the strong coupling regime compared to Thouless criterion.

Tc is nearly proportional to the Fermi energy regardless of interlayer coupling.

The approach reproduces essential features of underdoped high-temperature superconductors.

Abstract

We study the superconducting transition temperature $T_c$ of the bilayer d-p model with $d_{x^2-y^2}$-wavelike attractive interaction based on the formalism first employed by Nozi\`{e}res and Schmitt-Rink. In the strong coupling regime, $T_c$ obtained through this formalism are much suppressed, compared with those through Thouless criterion only. We also find that, whether the interlayer coupling exsists or not, $T_c$ is almost propotional to the Fermi energy in the strong coupling regime. Thus, we can reproduce the essential nature in the underdoped region.