Hot Spots and Pseudogaps for Hole- and Electron-Doped High-Temperature Superconductors

TL;DR

This paper explains the pseudogap phenomena in both electron- and hole-doped high-temperature superconductors using the two-dimensional Hubbard model, highlighting the importance of interaction strength and correlation length.

Contribution

It demonstrates that the spectral features and pseudogaps observed experimentally can be explained within the Hubbard model, emphasizing the role of interaction strength and correlation length.

Findings

Pseudogaps are explained by the Hubbard model at different coupling regimes.

Weak to intermediate coupling explains electron-doped systems at optimal doping.

Short-range correlations suffice at strong coupling to produce pseudogaps.

Abstract

Using cluster perturbation theory, it is shown that the spectral weight and pseudogap observed at the Fermi energy in recent Angle Resolved Photoemission Spectroscopy (ARPES) of both electron and hole-doped high-temperature superconductors find their natural explanation within the t-t'-t''-U Hubbard model in two dimensions. The value of the interaction U needed to explain the experiments for electron-doped systems at optimal doping is in the weak to intermediate coupling regime where the t-J model is inappropriate. At strong coupling, short-range correlations suffice to create a pseudogap but at weak coupling long correlation lengths associated with the antiferromagnetic wave vector are necessary.