Conductance noise of submicron wires in the regime of quantum Hall effect

A detailed study of low-temperature magnetoconductance in between quantized Hall plateaux is presented. The data are obtained for disordered two-terminal submicron wires defined in GaAs/AlGaAs heterostructures modulation-doped by Si. Slow time evolution of conductance G is observed on the high-field side of the quantized plateaux - for filling factors v < 3 and v < 2. This surprising noise is attributed to glassy dynamics of localized electrons in the wire centre, and to the corresponding time dependence of the impurity-assisted tunnelling probability between the current carrying regions. (C) 1998 Elsevier Science B.V. All rights reserved.