Leaky and mutually coupled quantum wires

In this paper, we investigate the effect on the transport in a quantum wire of short-ranged irregularities in the boundary. The results obtained are generalized to the case of a small hole in the boundary. Via such a hole, the wire is coupled to free two-dimensional space or to a second wire. Some interesting resonance features in the transmissivities are found and it is shown that the flux through the orifice exhibits narrow peaks at energies where quasibound states in one of the wires are possible. These fluxes are on the order of the currents inside the wire and thus should be measurable by experiment. We use a multiple-scattering formalism in terms of renormalized scattering amplitudes. This method turns out to be well suited for this kind of problem because it allows a very compact formulation, as has been shown in previous papers.