Fig. 3: Cooled, mixed and heated phases.
a–c Snapshots at two different times to outline the time evolution of configurations for cooled (A = 18.66 ± 0.08 μm), mixed (A = 18.88 ± 0.09 μm) and heated (A = 21.56 ± 0.09 μm) phases, respectively. The snapshots in the upper row are the initial configurations, with a corresponding to that in Fig. 1g, while the lower row reports the snapshot after 30 seconds of time evolution. In the lower row, the trajectories of two highlighted tracers (one inside and one outside the cluster) are displayed for each phase. Particles with low mobility are represented by orange trajectories while those with high mobility are shown in dark green. The evolution reveals that the cluster remains stable in the cooled and mixed phases but becomes transient in the heated phase due to the significantly higher particle mobility. d–f Velocity probability distributions p(v), shown for the corresponding phases in (a)–(c). The colored solid lines represent experimental data, while the black dashed lines correspond to results obtained by simulating the dynamics (1) in a confining circular arena. Parameters of the simulations are given in Table 1. Both the cooled and mixed phases exhibit a velocity peak near zero, with the mobile particles outside the cluster in the mixed state contributing to the distribution tail at higher velocities. In contrast, the heated phase shows a complete shift of the velocity peak away from zero.
