The interplay between a pseudogap and superconductivity in a two-dimensional Hubbard model

TL;DR

This study explores how antiferromagnetic correlations in a two-dimensional Hubbard model can simultaneously produce a pseudogap and enhance superconductivity, revealing their interconnected nature in strongly correlated electron systems.

Contribution

It demonstrates that antiferromagnetic correlations responsible for pseudogap formation can also promote higher superconducting critical temperatures in a Hubbard model.

Findings

Antiferromagnetic correlations lead to pseudogap formation at antinodal points.

Pseudogap and superconductivity are interconnected through shared antiferromagnetic origins.

Superconducting critical temperature Tc increases due to these correlations.

Abstract

Strongly correlated electrons systems may exhibit a variety of interesting phenomena, for instance, superconductivity and pseudogap, as is the case of cuprates and pnictides. In strongly correlated electron systems, it is considered essential to understand, not only the nature of the pseudogap, but also the relationship between superconductivity and the pseudogap. In order to address this question, in the present work, we investigated a one-band Hubbard model treated by the Green's function method within an n-pole approximation. In the strongly correlated regime, antiferromagnetic correlations give rise to nearly flat band regions in the nodal points of the quasiparticle bands. As a consequence, a pseudogap emerges at the antinodal points of the Fermi surface. The obtained results indicate that the same antiferromagnetic correlations responsible for a pseudogap, can also favor superconductivity, providing an increase in the superconducting critical temperature Tc.