Thermal ratchet effects in ferrofluids
arXiv:cond-mat/0405393 · doi:10.1103/PhysRevE.70.051107
Abstract
Rotational Brownian motion of colloidal magnetic particles in ferrofluids under the influence of an oscillating external magnetic field is investigated. It is shown that for a suitable time dependence of the magnetic field, a noise induced rotation of the ferromagnetic particles due to rectification of thermal fluctuations takes place. Via viscous coupling, the associated angular momentum is transferred from the magnetic nano-particles to the carrier liquid and can then be measured as macroscopic torque on the fluid sample. A thorough theoretical analysis of the effect in terms of symmetry considerations, analytical approximations, and numerical solutions is given which is in accordance with recent experimental findings.
18 pages, 6 figures
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Cited by in corpus (9)
- Artificial Brownian motors: Controlling transport on the nanoscale
- Tunable transport with broken space-time symmetries
- The Brownian gyrator: a minimal heat engine on the nano-scale
- Vortex and translational currents due to broken time-space symmetries
- Rotational properties of ferromagnetic nanoparticles driven by a precessing magnetic field in a viscous fluid
- Temperature effects on drift of suspended single-domain particles induced by the Magnus force
- Role of interactions in ferrofluid thermal ratchets
- Rotational ratchets with dipolar interactions
- Noiseless limit of a ferrofluid ratchet