Entropic resonant activation.

Varying cross section of confinement of a Brownian particle in two or higher dimensions results in an effective entropic barrier in reduced dimension. When the boundaries are subjected to periodic modulation, it is possible to observe a resonance of the mean first passage time between the lobes of a bilobal confined system as a function of the modulating frequency of the walls of the enclosure. The entropic resonant activation and the associated features, which are characteristic of the shape and size of the confinement, are amenable to a theoretical analysis in terms of a two-state model.