Diffusion anomalies in ac driven Brownian ratchets

Abstract

We study diffusion in ratchet systems. As a particular experimental realization we consider an asymmetric SQUID subjected to an external ac current and a constant magnetic flux. We analyze mean-square displacement of the Josephson phase and find that within selected parameter regimes it evolves in three distinct stages: initially as superdiffusion, next as subdiffusion and finally as normal diffusion in the asymptotic long-time limit. We show how crossover times that separates these stages can be controlled by temperature and an external magnetic flux. The first two stages can last many orders longer than characteristic time scales of the system thus being comfortably detectable experimentally. The origin of abnormal behavior is noticeable related to the ratchet form of the potential revealing an entirely new mechanism of emergence of anomalous diffusion. Moreover, a normal diffusion coefficient exhibits non-monotonic dependence on temperature leading to an intriguing phenomenon of thermal noise suppressed diffusion. The proposed setup for experimental verification of our findings provides a new and promising testing ground for investigating anomalies in diffusion phenomena.

version published in Phys. Rev. E, addendum included

References in corpus (9)

• Artificial Brownian motors: Controlling transport on the nanoscale
• Absolute negative mobility induced by thermal equilibrium fluctuations
• Observation of negative absolute resistance in a Josephson junction
• High efficiency deterministic Josephson Vortex Ratchet
• Brownian motors in micro-scale domain: Enhancement of efficiency by noise
• Anomalous transport in biased ac-driven Josephson junctions: Negative conductances
• GPU accelerated Monte Carlo simulation of Brownian motors dynamics with CUDA
• Josephson junction ratchet: effects of finite capacitances
• Efficiency of the SQUID Ratchet Driven by External Current

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