Hubbard model versus t-J model: The one-particle spectrum

TL;DR

This paper clarifies the differences between the Hubbard and t-J models' one-particle spectra, showing that wavefunction corrections and three-site terms reconcile their predictions, aligning well with experimental data for high-Tc cuprates.

Contribution

It introduces a comprehensive strong-coupling approach that includes wavefunction corrections and three-site terms to accurately match the Hubbard and t-J models' spectra.

Findings

Quantitative agreement between models achieved with corrections.

Numerical results for clusters up to 20 sites.

Photoemission spectra of Sr2CuO2Cl2 well described.

Abstract

The origin of the apparent discrepancies between the one-particle spectra of the Hubbard and t-J models is revealed: Wavefunction corrections, in addition to the three-site terms, should supplement the bare t-J. In this way a quantitative agreement between the two models is obtained, even for the intermediate-$U$ values appropriate for the high-Tc cuprate superconductors. Numerical results for clusters of up to 20 sites are presented. The momentum dependence of the observed intensities in the photoemission spectra of Sr2CuO2Cl2 are well described by this complete strong-coupling approach.