Incoherent multiple Andreev reflection in an array of SNS junctions

Last year, many interesting effects related to incoherent multiple Andreev reflection (MAR) were experimentally found, but only a few of them were theoretically explained. It was shown, for example, that if the voltage at the edges of a linear array is V, then subgarmonic structures in the current-voltage characteristics appear not only at the positions usual for the nonstationary Josephson effect, Vn = 2Δ/n, where n is integer, but also at voltages other than Vn. A step towards the description of the electron transport in a dirty array of SNS junctions is made in this letter. It is shown that subgarmonic structures may indeed appear at unusual voltages.