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Related papers: Ferrofluids as thermal ratchets

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We present results of molecular dynamics (MD) calculations of the effective thermal conductivity of nanofluids containing self-propelled nanoparticles. The translational and rotational dynamics observed in the simulations follow the…

Soft Condensed Matter · Physics 2024-06-19 Wei Peng , Anirban Chandra , Pawel Keblinski , Jeffrey L. Moran

The phenomenon of drift motion of single-domain ferromagnetic particles induced by the Magnus force in a viscous fluid is studied analytically. We use a minimal set of equations to describe the translational and rotational motions of these…

Mesoscale and Nanoscale Physics · Physics 2017-07-25 S. I. Denisov , B. O. Pedchenko , O. V. Kvasnina , E. S. Denisova

The transport of interacting Brownian particles in a periodic asymmetric (ratchet) substrate is studied numerically. In a zero-temperature regime, the system behaves as a reversible step motor, undergoing multiple sign reversals of the…

Statistical Mechanics · Physics 2008-12-31 Rogério M. da Silva , Clécio C. de Souza Silva , Sérgio Coutinho

Spin pumping by a moving magnetization gives rise to an electric voltage over a spin valve. Thermal fluctuations of the magnetization manifest themselves as increased thermal voltage noise with absorption lines at the ferromagnetic…

Mesoscale and Nanoscale Physics · Physics 2009-05-13 Jiang Xiao , Gerrit E. W. Bauer , Sadamichi Maekawa , Arne Brataas

We present a theory of magnetization reversal due to thermal fluctuations in thin submicron-scale rings composed of soft magnetic materials. The magnetization in such geometries is more stable against reversal than that in thin needles and…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Kirsten Martens , D. L. Stein , A. D. Kent

The motion of charged particles can be interfaced with electric circuitry via the current induced in nearby pick-up electrodes. Here we show how the rotational and translational dynamics of levitated objects with arbitrary charge…

Quantum Physics · Physics 2021-10-11 Lukas Martinetz , Klaus Hornberger , Benjamin A. Stickler

We study diffusion properties of an inertial Brownian motor moving on a ratchet substrate, i.e. a periodic structure with broken reflection symmetry. The motor is driven by an unbiased time-periodic symmetric force which takes the system…

Statistical Mechanics · Physics 2021-03-25 Jakub Spiechowicz , Marcin Kostur , Jerzy Łuczka

We demonstrate that a cycle of three holographic optical trapping patterns can implement a thermal ratchet for diffusing colloidal spheres, and that the ratchet-driven transport displays flux reversal as a function of the cycle frequency…

Soft Condensed Matter · Physics 2009-11-10 Sang-Hyuk Lee , Kosta Ladavac , Marco Polin , David G. Grier

Quantum effects fundamentally engender exotic physical phenomena in macroscopic systems, which advance next-generation technological applications. Rotational tunneling that represents the quantum phenomenon of the librational motion of…

Molecular dynamics simulations are used to simulate the thermal properties of a model fluid containing nanoparticles (nanofluid). By modelling transient absorption experiments, we show that they provide a reliable determination of…

Materials Science · Physics 2015-06-25 Mihail Vladkov , J. -L. Barrat

We study fluctuating tilt Brownian ratchets based on fractional subdiffusion in sticky viscoelastic media characterized by a power law memory kernel. Unlike the normal diffusion case the rectification effect vanishes in the adiabatically…

Statistical Mechanics · Physics 2012-06-04 Igor Goychuk , Vasyl Kharchenko

Superfluid spin transport $-$ dissipationless transport of spin $-$ is theoretically studied in a ferromagnetic insulator with easy-plane anisotropy. We consider an open geometry where spin current is injected into the ferromagnet from one…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 So Takei , Yaroslav Tserkovnyak

Using matter-wave interference, we have investigated thermal phase fluctuations in narrow coplanar, concentric rings of ultracold fermionic superfluids. We found that the correlation length decreases with number density, consistent with…

Quantum Gases · Physics 2024-07-08 Parth Sabharwal , Daniel G. Allman , Pradipta Debnath , Kevin C. Wright

We investigate analytically a microfluidic device consisting of a tube with non-uniform but spatially periodic diameter, where a fluid driven back and forth by a pump carries colloidal particles. Although the net flow of the fluid is zero,…

Soft Condensed Matter · Physics 2017-07-11 Frantisek Slanina

Molecular motors in biological systems are expected to use ambient fluctuation. In a recent Letter [Phys. Rev. Lett. {\bf 80}, 5251 (1998)], it was showed that the following question was unsolved, ``Can thermal noise facilitate energy…

Statistical Mechanics · Physics 2009-10-31 Fumiko Takagi , Tsuyoshi Hondou

We study a thermoelectric ratchet consisting of an array of disordered nanowires arranged in parallel on top of an insulating substrate, and contacted asymmetrically to two electrodes. Transport is investigated in the Mott hopping regime,…

Mesoscale and Nanoscale Physics · Physics 2016-04-13 Riccardo Bosisio , Geneviève Fleury , Jean-Louis Pichard , Cosimo Gorini

The ferrofluid dynamics theory is applied to thermodiffusive problems in magnetic fluids in the presence of magnetic fields. The analytical form for the magnetic part of the chemical potential and the most general expression of the mass…

Soft Condensed Matter · Physics 2009-11-10 Adrian Lange

We study the noise induced transport of an overdamped Brownian particle in frictional ratchet systems in the presence of external Gaussian white noise fluctuations. The analytical expressions for current and diffusion coefficient are…

Statistical Mechanics · Physics 2007-05-23 Raishma Krishnan , Debasis Dan , A. M. Jayannavar

We calculate the mesoscopic fluctuations of the magnetic anisotropy of ferromagnetic nanoparticles. A microscopic spin-orbit Hamiltonian considered as a perturbation of the much stronger exchange interaction first yields an explicit…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Gonzalo Usaj , Harold U. Baranger

Since the classical work by Purcell (1979) it has been generally accepted that most interstellar grains rotate suprathermally. Suprathermally rotating grains would be nearly perfectly aligned with the magnetic field by paramagnetic…

Astrophysics · Physics 2009-10-31 A. Lazarian , B. Draine