Fig. 4: Diffusion from a source to an active sink.
From: Active carpets drive non-equilibrium diffusion and enhanced molecular fluxes
Particles are spawned at a source (orange line) and subsequently diffuse to a sink (purple line) due to active fluctuations generated by the carpet, which is composed in this case of moving parallel Stokeslets. a Typical trajectory z(t) of a particle. Every time it hits the sink, we place it back at the source (events marked with *). b Steady-state distributions of the particle density for different source positions. Histograms show simulations and dashed lines are Eq. (10). c Diffusive flux as a function of distance. d Diffusive flux as a function of active fluctuation strength. For both c and d the markers show simulations and dashed lines show the prediction of Eq. (82).
