The pseudogaps in multiband electron-doped cuprate superconductivity

TL;DR

This paper analyzes pseudogap phenomena in electron-doped cuprate superconductors using a multiband model, revealing two distinct pseudogaps and their relation to phase diagram features and antiferromagnetic order.

Contribution

It introduces a nonrigid multiband model to explain the doping phase diagram and pseudogap behavior, highlighting two pseudogaps with different origins and their connection to superconductivity.

Findings

Identification of two pseudogaps with different doping dependencies

Correlation between pseudogaps and antiferromagnetic order suppression

Model predicts the vanishing pseudogap coincides with foreign carrier emergence

Abstract

The pseudogap (PG) excitations in the framework of multiband superconductivity are analysed. Calculations for the doping phase diagram of electron-doped cuprate superconductors have been made. A nonrigid multiband model has been used. The interband pairing acts between the upper Hubbard band (UHB) and midgap states created (and shifted upwards) by doping. The appearance of two PG and two phase diagram critical points (CP) is suggested. The larger antinodal PG reflects the destruction of the long-range antiferromagnetic (AF) order. The second, smaller PG is a near-nodal event with exposed doping dependence behind the first CP. It reaches the T$_c$ - dome. Model calculations have been made. The peculiarities of the phase diagram are determined by the doping-stimulated band overlap dynamics. The observation of ,,foreign`` carriers as compared to the ones introduced by doping is expected to start with the vanishing PG.