Enhanced thermodynamic efficiency in time asymmetric ratchets

Abstract

The energetic efficiency of an overdamped Brownian particle in a saw tooth potential in the presence of time asymmetric forcing is studied in the adiabatic limit. An error made in the earlier work on the same problem in literature is corrected. We find that asymmetry in potential together with temporal asymmetry in forcing leads to much enhanced efficiency without fine tuning of parameters. The origin of this is traced to the suppression of backward current. We also present a comparative study between the role of continuous and discontinuous ratchet forces on these measurable quantities. We find that the thermal fluctuations can optimize the energy transduction, the range of parameters, however, being very small. This ratchet model also displays current reversals on tuning of parameters even in the adiabatic regime. The possible relationships between nature of currents, entropy production and input energy are also addressed.

Stokes efficiency of temporally rocked ratchets

“…5 we plot η S as a function of temperature for a fixed F = 0.1 and temporal asymmetry ǫ = 0.9 but with varying potential asymmetry ∆. In most of the generic parameter space, we observe that temperature (or noise) facilitates η S which quite is opposite to the generically observed behavior of thermodynamic efficiency [25]. For example, if we take a particular curve say, ∆ = 0.0, F = 0.1, ǫ = 0.9, we can see that the value of efficiency is zero at T = 0.…”

Brownian motors: Joint effect of non-Gaussian noise and time asymmetric forcing

“…To be more specific, both the efficiency and current are zero up to a certain value of D, beyond which there is a finite current and efficiency with a peak value for a particular D in between and then with further increase in D there is a reduction in current and efficiency. This is at variance with the behavior of efficiency in presence of white noise for both sinusoidal and sawtooth potential [11][12][13].…”

“…Another line of work, also pointing towards efficiency enhancement, can be found in [11][12][13][14]. The system considered in these works include both time and space asymmetries [15], thereby finding a range of parameters where a remarkable efficiency enhancement is obtained.…”

Current reversal and mass separation of inertial Brownian motors in a two-noise ratchet

“…Simultaneously, the AMV is changed form positive to negative value. Therefore the Brownian particle can change its direction with increasing α and transport in not effective due to efficiency of the transport is zero or negative when the variance is larger than the AMV [45,46]. From Figs.…”