Spin–spin interaction effect in 2D Extended Hubbard Model

• An Extended Hubbard Model is proposed to study an antiferromagnetic correlated electrons system.
• An analytical diagonlization allows us to study J effect on the ground state and gap energies.
• The introduction of spin–spin interaction induces a supplementary conductivity.

Using an exact diagonlization for finite square lattice and taking into account the periodic boundary conditions in the two directions, we study the spin–spin interaction effect on some local electronic properties for antiferromagnetic correlated electrons system. We have considered an Extended Hubbard Model (EHM) including on-site coulomb interaction energy U and spin–spin interaction term J. The diagonlization of this 2D EHM model allows us to study J effect on some local properties for finite square lattice. The analysis of the obtained results shows that the introduction of spin–spin interaction induces a supplementary conductivity for antiferromagnetic correlated electrons system, even in the strong on-site interaction regime.