Scattering from defects in double quantum wires

The problem of elastic scattering from defects in a double quantum wire in an applied perpendicular magnetic field is investigated. It is shown that i n the range of energies when only one mode is propagating its "interference " with the evanescent mode leads to a possibility of both the resonant back scattering, corresponding to the maximum of reflection, and the perfect tra nsmission, when the amplitude of reflected wave vanishes. We found that the effect of perfect transmission can take place not only at the energies cor responding to the onset of the second propagating mode but also well inside the one-mode region, where it can reveal itself in transport properties. ( C) 1999 Elsevier Science Ltd. All rights reserved.