Wave Packet Propagation and Electric Conductivity of Nanowires

We compute the electric conductivity of nanowires in the presence of magnetic domain walls by the method of wave packet propagation. We demonstrate that the propagation through the wire depends on the initial state used in the wave packet simulation. We propose a procedure, based on the Landauer formula, to reduce this dependence. Direct numerical calculations of the Kubo formula for small individual systems are used as reference data for the proposed procedure. The enhancement of the conductivity in the magnetic domain wall is found in the present method in accordance with the previous perturbative analysis.