Classical mesoscopic conductance fluctuations in systems with boundary scattering

Abstract

Mesoscopic conductance fluctuations in a 2D electron channel due to correlations between classical boundary scattering processes are discussed. The contribution to conductance provided by the correlations is calculated and analysed; it is a consequence of the inherent roughness of the boundary. As a result stochastic oscillations for a weak magnetic field are exhibited. In the absence of bulk scattering the stochastic behaviour has a fractal structure, the fractal dimension being 1.5. It is shown that at higher temperatures classical mesoscopic fluctuations, discussed here, dominate over the universal conductance fluctuations. Unlike the universal conductance fluctuations, these classical ones are non-universal and reveal a dependence upon the geometry of a sample. Such non-universal behaviour of the classical conductance fluctuations is consistent with recent experimental data observed for ballistic conductors.