Transport in a one-dimensional chain with random fluctuating energies

The effect of temporal fluctuation on hopping transport is studied using a simple one-dimensional model of uniformly spaced localized sites with statistically independent random fluctuating site energies. Our main motivation for studying this model is the possibility that temporal fluctuations generated by electron-electron interactions in Anderson insulators may change the nature of the transport in these systems. We show that if the decrease of the fluctuation rate with temperature is less than exponential, then a crossover should occur from regular hopping transport at higher temperature, to some form of diffusive transport at lower temperature. We solve the model exactly for the case where the hopping transport is dominated by the largest activation energy, and we present a qualitative analysis for the more general case. The results could be relevant to the study of transport in narrow channel metal-oxide semiconductor field-effect transistors, amorphous films, and possibly chains of quantum dots. Furthermore, insight may be obtained in the problem of the metal-insulator transition.