title: Effect of a local perturbation in a fermionic ladder.
abstract: We study the effect of a local external potential on a system of two parallel spin-polarized nanowires placed close to each other. For single-channel nanowires with repulsive interaction we find that transport properties of the system are highly sensitive to the transverse gradient of the perturbation: the asymmetric part completely reflects the electrons leading to vanishing conductance at zero temperature, while the flat potential remains transparent. We envisage a possible application of this unusual property in the sensitive measurement of local potential field gradients.
authors.affiliation: Institut für Theorie der Kondensierten Materie and DFG Center for Functional Nanostructures, Karlsruher Institut für Technologie, 76128 Karlsruhe, Germany.
authors.forename: Sam T
authors.initials: ST
authors.lastname: Carr
authors.forename: Boris N
authors.initials: BN
authors.lastname: Narozhny
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Nersesyan