An efficient method for the analysis of electron waveguides

Recent experiments in mesoscopic systems have demonstrated a striking similarity between electronic devices and optical or microwave waveguides. In the absence of impurities and phase-breaking scattering, the geometry of such devices determines their behavior. These devices, which are usually composed of a network of guiding channels, can be analyzed in a manner similar to that used for electromagnetic waveguides. Sections of a device can be represented by scattering matrices, and individual scattering matrices can be combined, to determine the scattering matrix for an entire device. An efficient method is presented for the calculation of scattering matrices for devices with an arbitrary geometry. The method is applied to the analysis of a quantum reflection transistor, in which current is modulated between source and drain by a remote gate.