Metal-insulator transition of the one-dimensional extended Hubbard model

Abstract

Metal–insulator transition of the one-dimensional Hubbard model with both on-site U and nearest neighbor V interactions is studied by a combination of the numerical diagonalization method and the renormalization group (RG) method. Substituting the numerical result to the RG equation as the initial condition, we calculate the Luttinger-liquid parameter K ρ at quarter filling. Comparing the renormalized K ρ with the known exact result, we find it to be reliable in the strong coupling regime. This approach gives an evident critical point of the metal–insulator transition beyond the usual finite-size scaling for the numerical diagonalization result. The charge gap is also estimated by the numerical diagonalization method in the insulator region.