Fig. 2: Three dynamical regimes of active smectics defect evolution in closed cavities.
From: Defect dynamics in active smectics induced by confining geometry and topology
a–c Transitions between pinned, highly fluctuating (annihilation-nucleation), and self-rotating defect states with the increase of self-propulsion strength v0, in (a) circular, (b) epicycloid, and (c) hypocycloid cavities. Each regime is represented by sample snapshots of the spatial profiles of density field ψ obtained from simulations, with the ψ scale labelled by the color bars. In the mid panels the circled regions highlight the time-evolving process of boundary-induced defect generation. The bulk defects inside are labeled by white symbols, and boundary defects by black ones. Among them the square symbols indicate dislocations and the up or down triangles indicate ± 1/2 disclinations respectively. d Sample time variation of defect number density in the fluctuation regime at v0 = 0.31 (for system size of 512 × 512 grid points). e The corresponding normalized time correlation Cn(τ) of defect density, calculated over t = 105 − 106 and averaged over 80 simulations for each cavity. For a better illustration only the error-bar band for epicycloid of n = 6 cusps is shown, while those for other cases are of similar range.
