Gutzwiller wavefunction in the three-band Hubbard model: A variational Monte Carlo study

TL;DR

This study uses variational Monte Carlo to analyze the Gutzwiller wave function in a three-band Hubbard model, comparing results with Gutzwiller approximation, revealing significant differences at half-filling and good agreement elsewhere.

Contribution

It provides a detailed VMC analysis of the Gutzwiller wave function in the three-band Hubbard model, highlighting discrepancies with the Gutzwiller approximation especially at half-filling.

Findings

VMC results differ from GA at half-filling

Good agreement between VMC and GA away from half-filling

Doping affects the momentum distribution function

Abstract

The Gutzwiller wave function for the three-band Hubbard model on a two dimensional CuO$_2$ plane is studied by using the variational Monte Carlo (VMC) method in the limit $U_d \to \infty$, where $U_d$ is the Coulomb repulsion between holes on a Cu site. The VMC results for the energy and the fraction of $d$-holes are compared with those of the Rice-Ueda type Gutzwiller approximation (GA). The difference between the VMC and the GA results are most pronounced at half-filling, and away from half-filling the two results agree well in both the hole-doped and the electron-doped cases. The doping dependence of the momentum distribution function is also studied.