The enhancement of energy conversion efficiency and current reversal in the feedback coupled ratchets subject to harmonic forces

摘要

The directed transport of coupled Brownian particles in the feedback control protocol is investigated. To understand the properties of feedback coupled ratchets, we study how the centre-of-mass mean velocity and energy conversion efficiency are affected by the ratio of frequencies and amplitudes, phase difference of the two harmonic forces and coupling strength. It is found that the centre-of-mass mean velocity of coupled ratchets can achieve local maximum with the increase of harmonic force frequency, and the current can be promoted as the amplitude ratio increases. However, the diffusion of coupled particles could be suppressed effectively for the high frequency case. Furthermore, we can identify the enhancement of the coherency of transport and the energy conversion efficiency for intermediate values of the coupling constant, and the effects of differences in amplitude, frequency between the particles. Interestingly, there are the current reversal phenomenon with the increase of the ratio of harmonic force frequencies and amplitudes. These conclusions can provide some guidance in the enhancement of the transport performance of the artificial nanomachine.