(a) Bifurcation diagram of the mean recooling times for Ni=1–10 with error bars reflecting the s.e. For 2≤Ni≤6, statistically different recooling times are observed (indicative of regime II), which then converge for Ni≥7 (indicative of regime III). Shaded regions represent one s.e. about the mean recooling times for the control data and do not exhibit bifurcation. (b) Histograms of experimental recooling times accordingly convey the difference (2≤Ni≤6) and similarity (Ni≥7) in the steady-state temperatures. (c) Bifurcation diagram of steady-state temperatures, as calculated by a MD simulation using experimental conditions, is consistent with the experimentally observed bifurcated feature shown in a. Error bars represent the s.e. (d) MD-calculated traces showing the steady-state evolution for Ni=2 and 8, revealing the occurrence of steady-state ‘hopping’ in regime III. (e) Experimental observation of the bifurcation temperature Tu in regime II by varying the duration of the heating during hot initialization. Below (above) 100 ms of heating the recooling times are indicative of the cold (hot) steady state shown schematically by the blue (red) shaded region, and corresponds to Tu∼1-50 K. The grey region indicates the uncertainty associated with Tu and error bars represent s.e. As expected, data from regime III does not exhibit this abrupt increase in recooling times.