Entropic stochastic resonance of an active Brownian particle induced by periodically oscillating boundary

Abstract The dynamics of an active Brownian particle (ABP) subjected to a constant transverse force is numerically investigated in the confined geometry of a dumbbell-shape with periodically oscillating walls. The coherent factor Q is evaluated to characterize the response of the ABP to the periodic oscillation of the boundary. The simulation results indicate that Q as a function of the translational noise intensity, shows a non-monotonic behavior with the presence of a maximum in the drift-dominated regime where the transverse force exceeds the self-propulsion force, identifying the occurrence of the entropic stochastic resonance (ESR) phenomenon. The ESR effect can first be enhanced and then suppressed by increasing the self-propelled velocity, but too strong self-propelled motion destroys it in the activity-dominated regime. Increasing the rotational noise intensity strengthens the ESR effect with a saturation effect for higher rotational noise levels. The oscillation frequency and the phase lag between the left and right cells play similar roles in the ESR effect, i.e. by increasing these two parameters, the ESR effect is suppressed and eventually disappears. More interestingly, the presence of the transverse force is a necessary condition for the occurrence of the ESR but its variation plays a non-monotonic role in the ESR effect. Moreover, the transverse force also induces a resonance-like effect on Q for small noise levels in the drift-dominated regime. By increasing the static aspect ratio of the confinement space, the ESR effect can be enhanced, whereas the drift-induced resonant behavior is suppressed. Our results demonstrate that the boundary oscillating of the confinement may provide a feasible strategy for controlling the ABP in confined spaces through the ESR effect.