Resonant transport in pulsated devices: mobility oscillations and diffusion peaks

Diffusion of an overdamped Brownian particle on a symmetric periodic substrate is investigated in the presence of pulsated perturbations of two kinds: (i) Stepwise lateral displacements (flashing substrate) and (ii) instantaneous tilts (shot noise). Pulses are applied, as it is often observed, in either periodic or random sequences with assigned mean (bias) and average waiting time (time constant). For a given bias, both the diffusion coefficient and the mobility of the particle can be greatly enhanced by tuning the time constant. Moreover, also depending on the time constant, the mobility can grow negative in (i) or exceed unity in (ii). We term this phenomenon resonant transport.