Localização e espectro de absorção em sistemas eletrônicos com correlação tipo exponencial alongada na distribuição da desordem

Abstract

In this work, we study the problem of one-electron localization and optical absorption spectrum in 1d systems with correlated disorder. Our calculations were carried on chains with stretched exponential correlations on the disorder distribution. We perform exact numerical diagonalization to compute the participation number and the optical absorption spectrum. Our formalism provides an accurate estimate for the dependence of the localization length with the correlated disorder properties. In general lines, the localization length increases as the effective correlation length is increased. Our results about the optical absorption spectra reveal a interesting dependence of the absorption profile with the correlated disorder distribution. Our results suggest that as the disorder distribution becomes more correlated the absorption intensity is decreased. By using heuristic arguments we will explain this behavior in details. We obtain a simple relation between the optical absorption intensity and the localization length around the specific eigenmodes with largest oscillator strength. Numerical calculations of the optical absorption and the localization length gives support to our heuristic arguments.