Descete Spectrum of Delocalized States in One-Dimensional Random Potensial

It is well known$^{1,2}$ that in one-dimensional disordered system all states of electrons (or any other exitations) are localized. In this letter it is shown that delocalized states exist in a rather broad class of of simple models, but a set of delocalized states is not too great, and it does not contradict this theorem in more precize form$^{2,3}$. These systems can be considered as filters in energy for electrons.