Impact of rough potentials in rocked ratchet performance

Abstract

We consider thermal ratchets modeled by overdamped Brownian motion in a spatially periodic potential with a tilting process, both unbiased on average. We investigate the impact of the introduction of roughness in the potential profile, over the flux and efficiency of the ratchet. Both amplitude and wavelength that characterize roughness are varied. We show that depending on the ratchet parameters, rugosity can either spoil or enhance the ratchet performance.

Absorbed driven diffusion can provide positive heat and work output

“…The energy (Q out + W out ) equals the decrease of the particles energies, that is, it is given by the combination FLΔ which is always positive (cf figure 2(a)). One can confirm this time-asymptotic formulation of the first law by using the exact expressions (4), (13), and (17). The positive decrease of the particles energies still does not dictate the signs of the individual summands in (Q out + W out ).…”

“…As paradigmatic examples of this type of models can serve so-called rocking [10][11][12][13][14][15][16] and flashing [17][18][19][20][21][22][23][24][25][26][27][28] ratchets that are driven by sawtooth-like potentials with asymmetric energy barriers. Switching such a potential between two possible shapes, at least one of which is not symmetric, results in dynamics that can exhibit surprizing new features, namely the nonequilibrium fluctuation-induced transport, or to say, the possibility to extract mechanical work from the system.…”

Ratchet effects of a Brownian particle system with non-Gaussian noise driven by a biharmonic force

“…The theoretical and experimental investigations of ratchet transport of a Brownian particle have attracted much attention in recent years [1][2][3][4][5][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] for its wide range of potential applications. The transport phenomenon appears in many fields, such as in molecular motors, 2,5,[7][8][9][10][11][12] nanotechnologies of biological systems such as ion pumps, [25][26][27] artificial nanopores 28 and cold atoms in optical lattices, 29,30 etc.…”