The effect of a non-uniform scattering potential on conductance fluctuations in a quantum wire

We investigate experimentally the fluctuations of the conductance of a high mobility quantum wire. We show that scattering of electrons is not evenly distributed across the wire. In the centre of the wire electrons propagate almost ballistically. However, when the electrons are forced into the boundaries of the wire diffusive scattering occurs. This is seen as a dramatic enhancement of the variance and characteristic period of the fluctuations at the field at which maximum boundary scattering is predicted. We compare our results with recent theories and construct an empirical model to describe the transport processes in the wire. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.