Figure 1

(Color online) The fractional change in the nonohmic characteristic of $200\text{−}\mathrm{\AA }$-thick ${\mathrm{In}}_2{\mathrm{O}}_{3-x}:\mathrm{Au}$ sample measured at different temperatures (marked on each curve). Sample length is $L=3500\mu \mathrm{m}$ and width $W=1\mathrm{mm}$. Top panel: The differential resistance [defined in Eq. (1) as a function of the voltage]. Bottom panel: The same data plotted as function of $F(=V∕L)$ normalized by $T^2$. Note the near perfect data collapse as well as the fit to formula (20) represented by the continuous line.Reuse & Permissions

Figure 2

(Color online) Resistance versus temperature for the sample of Fig. 1 (open squares) and for a ${\mathrm{In}}_2{\mathrm{O}}_{3-x}:\mathrm{Au}$ sample with length $L=80\mu \mathrm{m}$ and width $W=500\mu \mathrm{m}$ (full circles). The dashed lines are the logarithmic slopes used in defining the value of $\gamma$ [see Eq. (19)].Reuse & Permissions

Figure 3

(Color online) Dependence of the differential resistance on voltage at several temperatures. ${\mathrm{In}}_2{\mathrm{O}}_{3-x}:\mathrm{Au}$ sample with length $L=80\mu \mathrm{m}$ and width $W=500\mu \mathrm{m}$. The noisier data here (as compared with those of Fig. 1), is mainly due to the much smaller sample size.Reuse & Permissions

Figure 4

(Color online) Top panel: The differential resistance versus the voltage $V$ normalized by the temperature $T$ using the data of Fig. 3. The full line is a best fit to the data using Eq. (22). Note the data collapse for the three lowest temperatures and the deviations from the short-sample behavior at $T=837\mathrm{mK}$. Bottom panel: Data from the same figure (Fig. 3) plotted as a function of $F(=V∕L)$ normalized by $T^2$. The full line is a best fit to the data using Eq. (20). Note the data collapse for the two highest temperatures and the deviations from the long-sample behavior at $T=279\mathrm{mK}$. For clarity of presentation, the data for $T=620\mathrm{mK}$ $\left(386\mathrm{mK}\right)$ were eliminated from the top (bottom) panels, respectively.Reuse & Permissions