Resonating Hartree-Fock theory of a one-dimensional electronic system

Abstract

A new method to treat large electronic quantum fluctuations, the resonating Hartree-Fock (HF) method, is applied to the one-dimensional (1D) Hubbard model. In the half-filled case, we consider soliton-antisoliton (SS) pairs as quantum fluctuations in the spin density wave (SDW) making quantum translational and breathing motions, resonating breathers. The resonating breathers explain 76.5% ( U=3) and 70.1% ( U=4) of the ground state correlation energy, which are better results than the Gutzwiller method. They also explain the short range decrease in the spin correlation function and give low energy excited states that are similar to those in polyenes.