Correlated band structure of electron-doped cuprate materials

TL;DR

This study uses advanced numerical methods to analyze how the spectral function of electron-doped cuprates varies with doping, emphasizing the importance of strong correlations for accurate modeling.

Contribution

It applies a variational cluster-perturbation theory approach to the Hubbard model, providing a consistent description of ARPES data without doping-dependent interactions.

Findings

Spectral functions match ARPES experiments across doping levels.

Strong electronic correlations are essential for accurate spectral descriptions.

No doping-dependent U needed for modeling the spectra.

Abstract

We present a numerical study of the doping dependence of the spectral function of the n-type cuprates. Using a variational cluster-perturbation theory approach based upon the self-energy-functional theory, the spectral function of the electron-doped two-dimensional Hubbard model is calculated. The model includes the next-nearest neighbor electronic hopping amplitude $t'$ and a fixed on-site interaction $U=8t$ at half filling and doping levels ranging from $x=0.077$ to $x=0.20$. Our results support the fact that a comprehensive description of the single-particle spectrum of electron-doped cuprates requires a proper treatment of strong electronic correlations. In contrast to previous weak-coupling approaches, we obtain a consistent description of the ARPES experiments without the need to introduce a doping-dependent on-site interaction $U$.