Control of thermal current in the Brownian heat pump

Abstract

Here heat conduction in the Brownian heat pump (BHP) driven by external periodic forces is investigated. By means of numerical simulation, we found that thermal current of the BHP can be controlled by means of the external periodic forces. As phase shift ϕ of the BHP takes smaller values, if one end of the BHP is regulated only by one periodic force, the thermal current can go from the end to the other end of the BHP. Whereas for the greater values of ϕ , the thermal current can go from the other end to the end adjusted by the periodic force. With the increment of amplitude of the periodic force, a thermal current reversal phenomenon takes places in the BHP. In the system, there also exists a critical phenomenon about ϕ , at whose critical point its thermal current is almost equal to zero no matter how the amplitude of the periodic force is changed. If the two ends of the BHP are adjusted simultaneously by their own periodic forces, its thermal current takes both positive and negative values, and oscillates periodically with the phase difference between the two periodic forces. The results will possess a crucial significance in understanding performance mechanisms of nano-machines and organisms.