English
Related papers

Related papers: Ferrofluids as thermal ratchets

200 papers

The thermal stability in nanostructured magnetic systems is an important issue for applications in information storage. From a theoretical and simulation perspective, an accurate prediction of thermally-activated transitions is a…

Mesoscale and Nanoscale Physics · Physics 2021-01-04 L. Desplat , J. -V. Kim

In the presence of spatial variation of the magnetization direction, electric current noise causes a fluctuating spin-transfer torque that increases the fluctuations of the ferromagnetic order parameter. By the fluctuation-dissipation…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Jorn Foros , Arne Brataas , Yaroslav Tserkovnyak , Gerrit E. W. Bauer

Thermal fluctuations can play an important role in the buckling of elastic objects at small scales, such as polymers or nanotubes. In this paper, we study the finite-temperature buckling transition of an extensible rod by analyzing…

Soft Condensed Matter · Physics 2016-01-06 Deshpreet Singh Bedi , Xiaoming Mao

We propose and study a novel way to produce a DC transport of vortices when applying an AC electrical current to a sample. Specifically, we study superconductors with a graduated random pinning density, which transports interacting vortices…

Superconductivity · Physics 2009-11-07 C. J. Olson , C. Reichhardt , B. Janko , Franco Nori

Large heat currents are obtained in Co/Cu/Co spin valves positioned at the middle of Cu nanowires. The second harmonic voltage response to an applied current is used to investigate the effect of the heat current on the switching of the spin…

Mesoscale and Nanoscale Physics · Physics 2015-03-13 Haiming Yu , Simon Granville , Dapeng Yu , Jean-Philippe Ansermet

A minimal system of equations is introduced and applied to study the drift motion of ferromagnetic particles suspended in a viscous fluid and subjected to a time-periodic driving force and a nonuniformly rotating magnetic field. It is…

Soft Condensed Matter · Physics 2017-02-02 S. I. Denisov , B. O. Pedchenko

The theory of elastic magnets is formulated under possible diffusion and heat flow governed by Fick's and Fourier's laws in the deformed (Eulerian) configuration, respectively. The concepts of nonlocal nonsimple materials and viscous…

Mathematical Physics · Physics 2018-05-09 Tomas Roubicek , Giuseppe Tomassetti

We demonstrate the possibility to rectify the nanoscale radiative heat flux between two nanoparticles by coupling them with the nonreciprocal surface modes of a magneto-optical substrate in a Voigt configuration. When the non-reciprocal…

Mesoscale and Nanoscale Physics · Physics 2019-04-30 Annika Ott , Riccardo Messina , Philippe Ben-Abdallah , Svend-Age Biehs

Magnetic skyrmions are particle-like objects with topologically-protected stability which can be set into motion with an applied current. Using a particle-based model we simulate current-driven magnetic skyrmions interacting with random…

Strongly Correlated Electrons · Physics 2017-08-09 Sebastian A. Diaz , C. J. O. Reichhardt , Daniel P. Arovas , Avadh Saxena , C. Reichhardt

The experimental application of fluctuation theorem (FT) on nanometer to submicrometer sized systems has received thorough attention in the past several years. Nonetheless, the employment of FT on self-propelling objects has seldom been…

Statistical Mechanics · Physics 2011-05-02 R. Suzuki , H. R. Jiang , M. Sano

In the present Letter we investigate the heat and momentum fluxes radiated by a hot magneto-optical nanoparticle in its surrounding under the action of an external magnetic field. We show that the flux lines circulate in a confined region…

Mesoscale and Nanoscale Physics · Physics 2018-05-16 Annika Ott , Philippe Ben-Abdallah , Svend-Age Biehs

Molecular motors are known to have the high efficiency of energy transformation in the presence of thermal fluctuation. Motivated by the surprising fact, recent studies of thermal ratchet models are showing how and when work should be…

Soft Condensed Matter · Physics 2009-10-31 Hideki Kamegawa , Tsuyoshi Hondou , Fumiko Takagi

Using analytical calculations, we characterize the rotational behavior of a rigid spherical particle when subject to a net external torque in a continuous viscoelastic environment. On long time scales, the embedding medium can either…

Soft Condensed Matter · Physics 2021-08-30 S. K. Richter , C. D. Deters , A. M. Menzel

In this work, we combine conventional linear response time-domain THz spectroscopy with non-linear THz-pump THz-probe techniques to study metallic strained thin films of $\mathrm{Ca}_2\mathrm{RuO}_4$, which undergo a transition into a…

The existence of high-temperature ferromagnetism in thin films and nanoparticles of oxides containing small quantities of magnetic dopants remains controversial. Some regard these materials as dilute magnetic semiconductors, while others…

Materials Science · Physics 2015-05-18 J. M. D. Coey , P. Stamenov , R. D. Gunning , M. Venkatesan , K. Paul

The miniaturisation of magnetic read heads and random access memory elements makes them vulnerable to thermal fluctuations. We demonstrate how current-induced spin-transfer torques can be used to suppress the effects of thermal…

Mesoscale and Nanoscale Physics · Physics 2011-03-07 Swarnali Bandopadhyay , Arne Brataas , Gerrit E. W. Bauer

We explore the derivation of interatomic exchange interactions in ferromagnets within density-functional theory (DFT) and the mapping of DFT results onto a spin Hamiltonian. We delve into the problem of systems comprising atoms with strong…

Materials Science · Physics 2013-10-10 Marjana Lezaic , Phivos Mavropoulos , Gustav Bihlmayer , Stefan Blügel

We discuss the usage of ratchet mechanisms to transport a continuous phase in several micro-fluidic settings. In particular, we study the transport of a dielectric liquid in a heterogeneous ratchet capacitor that is periodically switched on…

Soft Condensed Matter · Physics 2010-11-30 Uwe Thiele , Karin John

The comprehensive search for multifunctional materials has resulted in the discovery of semiconductors and oxides showing ferromagnetic features persisting to room temperature. In this tutorial review the methods of synthesis of these…

Materials Science · Physics 2011-01-12 Alberta Bonanni , Tomasz Dietl

Brownian motors, or ratchets, are devices which "rectify" Brownian motion, i.e. they can generate a current of particles out of unbiased fluctuations. The ratchet effect is a very general phenomenon which applies to a wide range of physical…

Statistical Mechanics · Physics 2011-12-06 F. Renzoni