Approximate expression for the ground-state energy of the two- and three-dimensional Hubbard model at arbitrary filling obtained from dimensional scaling

J Phys Condens Matter. 2019 Nov 13;31(45):455601. doi: 10.1088/1361-648X/ab32ac. Epub 2019 Aug 12.

Abstract

We generalize the linear discrete dimensional scaling approach for the repulsive Hubbard model to obtain a nonlinear scaling relation that yields accurate approximations to the ground-state energy in both two and three dimensions, as judged by comparison to auxiliary-field quantum Monte Carlo (QMC) data. Predictions are made for the per-site ground-state energies in two and three dimensions for n (filling factor) and U (Coulomb interaction) values for which QMC data are currently unavailable.