Ballistic transport through a double bend in an electron waveguide

Publisher Website
Google Scholar
Abstract
The transport properties of a double bend in a two-dimensional electron waveguide are investigated by performing calculations of the transmission and conductance. The bends can introduce significant mode mixing at energies high enough for multimode transport. If the bent regions become fully circular, the bends introduce almost no additional resistance to the current flow except for energies very close to one of the thresholds for propagation in the channel. There are extremely narrow dips in conductance just below the threshold energies for the next channel. Bound states are found in the bent regions. We consider the spatial distribution of currents and show that complicated flow patterns with vortex structures appear at conductance dips. When bend regions are not fully circular, the conductance dips are considerably broadened and a series of superimposed resonant peaks is found. The results are in qualitative agreement with recent measurements.