Coherent transport of interacting electrons through a single scatterer

Using the self-consistent Hartree-Fock method, we calculate the persistent current of weakly interacting spinless electrons in a one-dimensional ring containing a single delta barrier. We find that the persistent current decays with the system length (L) asymptotically like I proportional to L-1-alpha, where alpha > 0 is the power depending only on the electron-electron interaction. We also simulate tunneling of the weakly interacting one-dimensional electron gas through a single delta barrier in a finite wire biased by contacts. We find that the Landauer conductance decays with the system length asymptotically like L-2 alpha. The power laws L-1-alpha and L-2 alpha have so far been observed only in correlated models. Their existence in the Hartree-Fock model is thus surprising. (c) 2006 Elsevier B.V. All rights reserved.