Tunable anomalous transports by Friction and Noise

We numerically investigate the anomalous transports of an inertial Brownian particle moving in a spatial-periodic symmetric system under the influence of a time-periodic force and a constant bias. The system is also driven by nonequilibrium fluctuation and friction fluctuation, which are correlated with each other. We find that a time-periodic force plays a key role in anomalous transports and that the correlation between noises can enhance, weaken, or lead to negative mobility (NM) and ratchet effect (RE). Moreover, our findings suggest that NM can be tuned by friction and Gaussian noise in certain parameter ranges and explained by the temporally periodic transient probability distributions (TPTPD) of the particle’s velocity and position, average trajectory, and time-dependent diffusion coefficient (TDDC). The TPTPD reveals that system dynamics is sensitive to the initial conditions and system parameters. Initial transient states display that the particle undergoes superdiffusion firstly and then becomes normal diffusion. Additionally, the small TDDC corresponds to anomalous mobility, whereas the large TDDC corresponds to normal mobility. To obtain more intuition and generality, we also study the mobilities via the mobility coefficient. Our findings may be applied for particles sorting, particles separation, control of molecular motors, etc.