Résumé en anglais

We consider two models of one-dimensional random walks among biased i.i.d. random conductances: the first is the classical exponential tilt of the conductances, while the second comes from the effect of adding an external field to a random walk on a point process (the bias depending on the distance between points). We study the case when the walk is transient to the right but sub-ballistic, and identify the correct scaling of the random walk: we find α∈[0,1] such that logXn/logn→α. Interestingly, α does not depend on the intensity of the bias in the first case, but it does in the second case.