One-dimensional strongly interacting electrons with single impurity:   conductance reemergence
  We show that conductance of 1D channel with one point-like impurity critically depends on asymptotic behavior of e-e interaction at small momenta k (about inverse length of a channel). Conductance reemerges (contrary to the case of point-like repulsive potential) if potential V(k=0)= 0. For example, this happens if the bare e-e interaction is screened by the charges in the bulk. The relation of this phenomena to the long-range order present in the Luttinger model is discussed. 
V.V. Afonin, V.Yu Petrov
cond-mat.str-el