2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/16501We theoretically study the nonlinear optical response and photoexcited states of the Mott insulators. The nonlinear optical susceptibility χ^(3) is calculated by using the exact diagonalization technique on small clusters. From the systematic study of the dependence of χ^(3) on dimensionality, we find that the spin-charge separation plays a crucial role in enhancing χ^(3) in the one-dimensional (1D) Mott insulators. Based on this result, we propose a holon-doublon model, which describes the nonlinear response in the 1D Mott insulators. These findings show that the spin-charge separation will become a key concept of optoelectronic devices.5 pages with 3 figures, to appear in PRB RC, 15 August 2000Strongly Correlated ElectronsMaterials Sciencetext