Delocalization-localization transition in a one-dimensional two-hand model with random clusters

We investigate the delocalization-localization transition in a one-dimensional disordered system with two hybridized bands. The effects of both disorder and interband hybridization on the energy spectrum and the properties of wavefunctions are studied by using the improved Dean method and the second-moment formula. The results show that there exist band tails in the gap regions. All subbands are widened by increasing the disorder strength, whereas when the interband hybridization increases, some subbands become narrower and the others are widened. The delocalization of the wavefunctions tends to be enhanced as the hybridization increases. The localization-delocalization transition of the wavefunctions occurs when the interband hybridization becomes larger than a critical value. The competition between disorder and hybridization determines the nature of the electronic states and the energy spectrum.