Perturbation Calculation of two-electron interaction in the ground of the Hubbard Model

Abstract

The single-band Hubbard model was studied in one dimensional lattice system which consist only of two sites. The perturbation calculation accounts for the ground state energy and its wave functions .The exact and perturbation calculation are in agreement when the value of the on-site coulomb interaction U is equal to zero.

Keywords: Hubbard model, Perturbation, electrons, and creation and annihilation operators.