ac-Conductivity of aperiodic chains re-examined

ac-Conductivity of infinite quasiperiodic chanins have been calculated using the Miller-Abrahams equations and a real space decimation technique. Our approach deals with the infinite lattice directly, instead of calculating the conductivity for periodic repetitions of long quasiperiodic segments, as has been done recently. We point out an interesting observation that, some aperiodic chains show the same analytical behaviour in the low frequency ac-conductivity as an ordered chain, whereas, some others behave in a totally different way. We explain this observation from a renormalization group point of view.