A coupled transport model of Brownian motors driven by two periodic forces

A coupled transport model of Brownian motors driven by two periodic forces is established. The effects of the two periodic forces on the cooperative transport behaviours of Brownian motors are investigated, including the frequencies and intensities. The results show that when the frequencies of periodic forces are all too large or too small, the directed transport of the motors system can't appear, and appropriate frequencies can promote the transport. Otherwise, with increasing the intensities of periodic forces, the directed transport is more and more obvious. In addition, the effect of a constant force is discussed. It is found that the constant force on the non ratchet potential can't offer effective energy for the directed transport of system, but the constant force on the ratchet potential can offer.