Fig. 4. Analyzing ergodicity via the stress metric.

a Inverse stress metric ${\mathrm{\Omega }}^{-1}\left(\mathrm{t}\right)$ plotted for each temperature as a function of time on a log-log scale. b Exponent z describing the stress metrics’ decays extracted by ordinary linear least squares fits of the stress metrics. Error bars emerge from the standard error of fit. c–e Heatmaps depicting the frequency of nanoisland evolutions at (c) 250 K, (d) 270 K, and (e) 300 K. Nanoislands that are purely red fluctuate at ten times or more during the experiment duration while those that are purely black do not fluctuate at all.