Short Communication

Effect of coupling to the leads on the conductance fluctuations in one-dimensional disordered, mesoscopic systems

(Received 22 November 1993, revised 21 June 1994, accepted 28 July 1994)

Abstract
We study the electronic transport in a one-dimensional disordered chain with both site-diagonal and off-diagonal (hopping) disorder, the latter being perfectly correlated to the diagonal disorder at the nearest neighbor sites in a linear fashion. Since we allow the hopping in the perfect leads to be different from the average hopping in the sample, the average two-probe conductance ( < g >) and the conductivity ( ) decay non-monotonically with length. Because the peak regions of conductivity represent nearly constant s, these domains are quasi-Ohmic with their "effective" mean free paths equal to the stationary values of in these domains. Indeed, when < g > passes through these quasi-Ohmic regions, the standard deviation of g latches on to almost constant values of about 0.3e²/h, appropriate for 1D (as observed by us in a recent paper). The evolution of the probability distribution P(g) with length demonstrates that it is unusually broad (nearly uniform) around the first quasi-diffusive regime and that for larger lengths, P(g) narrows down in general, but becomes non-monotonically broader whenever peaks up again, i.e., around the other (than the first) quasi-diffusive regimes.