Brownian motor efficiency enhanced by nonequilibrium noise

We study transport properties of an inertial Brownian motor which moves in a symmetric spatially periodic potential and is subjected to both a symmetric, unbiased time-periodic driving α cos (ωt) and a static constant force F or, likewise, nonequlibrium noise of equal mean value 〈(η(t)〉 = F. We focus on the efficiency of the motor and discuss various definitions. We show that within selected parameter regimes, nonequilibrium noise η (t) can be significantly more effective than the deterministic force F. This implies that the motor moves much faster and its efficiency distinctly increases. These features are independent of the assumed Brownian motor efficiency measure. We demonstrate this feature with detailed simulations by resource to generalized white Poissonian noise. Our theoretical results can be tested and corroborated experimentally by use of a setup that consists of a resistively and capacitively shunted Josephson junction.