Pseudogap Formation in an Electronic System with d-wave Attraction at Low-density

TL;DR

This paper investigates pseudogap formation in a low-density electronic system with d-wave attraction, revealing a gap-like structure above the superconducting transition related to Cooper-pair binding energy.

Contribution

It demonstrates that a pseudogap appears in spectral functions at high temperature and strong coupling, linked to Cooper-pair binding energy, using a self-consistent t-matrix approach.

Findings

Pseudogap appears above the transition temperature in spectral functions.

The pseudogap energy scale is set by Cooper-pair binding energy.

Gap-like structures are observed in low-density d-wave systems.

Abstract

On the basis of an electronic model with separable attractive interaction, the precursors at high temperature and strong coupling of the d-wave superconducting state are investigated in the one-particle spectral function $A({\bf k},\omega)$ and the total density of states $\rho(\omega)$, with the use of the self-consistent $t$-matrix approximation. In the low-density region, it is found that a gap-like structure at the Fermi level appears in $A({\bf k},\omega)$ and $\rho(\omega)$ above the superconducting transition temperature. It is shown that the pseudogap energy scale is determined by the binding energy of the Cooper-pair.