Off-site interaction effect in the Extended Hubbard Model with SCRPA method

The Self Consistent Random Phase Approximation (SCRPA) and a Direct Analytical (DA) method are proposed to solve the Extended Hubbard Model in 1D. We have considered an Extended Hubbard Model (EHM) including on-site and off-site interactions for closed chains in one dimension with periodic boundary conditions. The comparison of the SCRPA results with ones obtained by a Direct Analytical approach shows that the SCRPA treats the problem of these closed chains with a rigorous manner. The analysis of the nearest-neighbour repulsion effect on the dynamics of our closed chains shows that this repulsive interaction between the electrons of the neighbouring atoms induces supplementary conductivity, since, the SCRPA energy gap vanishes when these closed chains are governed by a strong repulsive on-site interaction and intermediate nearest-neighbour repulsion.