Repulsive binary alloys and the absence of localization: Application to Fibonacci lattices and molecularly based electronic filters
We show here that a static disordered binary alloy in which one of the impurities is prevented from clustering in the lattice as a result of strong repulsive interactions, e.g., will possess a localization-delocalization transition regardless of the spatial dimension. We show explicitly that (N)1/2 of the electronic states are completely unscattered by the disorder and lead to superdiffusive transport with a mean-square displacement growing in time as t3/2 over a wide range of the static disorder in one dimension. The model is shown to be applicable to electron transport in Fibonacci lattices fabricated from two kinds of materials such as GaAs and AlAs. It is shown explicitly that transient grating experiments can be used to probe the location of the unattenuated states in the energy band. We propose that this model can be used to design molecularly based electronic filters.