Temperature dependence of universal conductance fluctuations in narrow mesoscopic Si inversion layers

The temperature dependence of magnetoconductance fluctuations in narrow mesoscopic silicon inversion layers (length 4.3 μm, width 0.14 and 0.43 μm) has been studied. The magnitude and magnetic correlation length of the fluctuations was measured in the temperature range T=0.2–4.2 K and for magnetic fields up to 3 T. Weak-localization experiments were performed for an independent determination of the inelastic diffusion length $L_{\mathrm{in}}$. When $L_{\mathrm{in}}$ exceeds the channel width W [quasi-one-dimensional (quasi-1D)] the experimental temperature dependence of the fluctuation amplitude and magnetic correlation length is very well described by the theory for universal conductance fluctuations of Lee and Stone. In case $L_{\mathrm{in}<\mathrm{W}}$ (quasi-2D) a good agreement with this theory is found for the temperature dependence of the fluctuation amplitude.