Electron glass in samples approaching the mesoscopic regime

We study the dependence of the glassy properties of strongly localized In2 O3-x films on the sample lateral dimensions. Characteristic mesoscopic effects such as reproducible conductance fluctuations (CFs) are readily observable in gated structures for sample size smaller than 100 μm measured at 4 K, and the relative amplitude of the CF decreases with the sample volume as does the flicker noise. By contrast, down to sample size of a few microns, the nonequilibrium features that are attributed to the electron glass are indistinguishable from those observed in macroscopic samples, and in particular, the relaxation dynamics is independent of sample size down to 2 μm. In addition, the usual features that characterize the electron glass including slow relaxation, memory effects, and full-aging behavior are all observed in the "mesoscopic" regime, and they appear to be independent of the conductance fluctuations.