Ground-state properties of the Hubbard model by Lanczos diagonalizations

摘要: We investigate the Hubbard model on a two-dimensional cluster of 18 sites using Lanczos algorithm for different strengths Coulomb repulsion in low doping region. Energies and correlation functions are given half-filling two holes. In strong coupling regime we compare our results with $t\ensuremath{-}J$ model. confirm tendency holes to repel, although significant value ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$-wave superconductive order parameter is measured. These data represent benchmark future quantum simulations.