Single-Particle Spectrum in the Electron-Doped Cuprates

TL;DR

This paper investigates how the single-particle spectrum evolves with electron doping in cuprates, revealing the emergence of Fermi surface pockets and in-gap states consistent with experimental ARPES data.

Contribution

It introduces a scheme incorporating transverse spin excitations into mean-field theory, providing a detailed explanation of spectral features in electron-doped cuprates.

Findings

Small Fermi surface pockets appear around X-points with doping.

In-gap states develop into a quasiparticle band near the chemical potential.

Results align well with ARPES experimental observations.

Abstract

We study the evolution of the single-particle spectrum with electron doping in a scheme which adds multiple exchange of transverse spin excitations to the mean-field antiferromagnetic insulator. Away from half-filling small Fermi surface pockets appear first around the X-points, and simultaneously new spectral weight grows in the insulating gap. With further doping the in-gap states develop the character of a renormalized quasiparticle band near the chemical potential. The essential features in momentum-energy space agree well with recent studies using angle-resolved photoemission spectroscopy on electron-doped cuprates. We interpret the origins and the nature of the in-gap states using a simple variational wavefunction.