Related papers: Thermal fluctuations of magnetic nanoparticles
Laser induced modulation of the magnetization dynamics occurring over various time-scales have been unified here for a Ni80Fe20 thin film excited by amplified femtosecond laser pulses. The weak correlation between demagnetization time and…
We investigate the role of thermal fluctuations and of the finite number of monomers in small clusters of carbon atoms on the nucleation rate of carbonaceous grains. Thermal fluctuations are due to the quantized nature of the energy…
Systems of many nanoparticles or volume-discretized bodies exhibit collective radiative properties that could be used for enhanced, guided, or tunable thermal radiation. These are commonly treated as assemblies of point dipoles with…
A set of equations describing the motion of a free magnetic nanoparticle in an external magnetic field in a vacuum, or in a medium with negligibly small friction forces is postulated. The conservation of the total particle momentum, i.e.…
We theoretically investigate the thermally induced back-action effects in absorption-sensitive micro- and nanomechanical resonators. We propose a unified approach, enabling to simultaneously address both the effective dynamics and…
Micromagnetics simulation based on the classical Landau-Lifshitz-Gilbert (LLG) equation has long been a powerful method for modeling magnetization dynamics and reversal of three-dimensional (3D) magnets. For two-dimensional (2D) magnets,…
We present a simple simulation model for analysing magnetic and frictional losses of magnetic nano-particles in viscous fluids subject to alternating magnetic fields. Assuming a particle size below the single-domain limit, we use a…
Colloidal suspensions of ferromagnetic nano-particles, so-called ferrofluids, are shown to be suitable systems to demonstrate and investigate thermal ratchet behavior: By rectifying thermal fluctuations, angular momentum is transferred to a…
We establish an effective Markov theory for the rotational Brownian motion of hot nanobeads and nanorods. Compact analytical expressions for the effective temperature and friction are derived from the fluctuating hydrodynamic equations of…
A sensor for thermal and thermodynamic measurements of small magnetic systems have been designed and built. It is based on a 5μm-thick suspended polymer membrane, which has a very low heat capacity (≈ 10-6 J/K at nitrogen…
The condition of thermal equilibrium simplifies the theoretical treatment of fluctuations as found in the celebrated Einstein's relation between mobility and diffusivity for Brownian motion. Several recent theories relax the hypothesis of…
Numerous authors have referred to room-temperature magnetic switching of large electric polarizations as The Holy Grail of magnetoelectricity.We report this long-sought effect using a new physical process of coupling between magnetic and…
An electromagnetic theory of thermal radiation is outlined, based on the fluctuation electrodynamics of Rytov and co-workers. We discuss the basic concepts and the status of different approximations. The physical content is illustrated with…
Using a combination of single-crystal neutron scattering and reverse Monte Carlo refinements, we study the magnetic structure of paramagnetic MnO at a temperature (160\,K) substantially below the Curie-Weiss temperature…
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…
We discuss the interplay between anti-ferromagnetic order and polarization fluctuations in a magnetic quantum paraelectric. Using an action where anti-ferromagnetic order parameter couples to the polarization fluctuations and as well as…
Following the demonstration of laser-induced ultrafast demagnetization in ferromagnetic nickel, several theoretical and phenomenological propositions have sought to uncover its underlying physics. In this work we revisit the three…
We have shown that polarized neutron reflectometry can determine in a model-free way not only the mean magnetization of a ferromagnetic thin film at any point of a hysteresis cycle, but also the mean square dispersion of the magnetization…
We have determined the temperature evolution of the spin and orbital moments in the zero magnetization ferromagnet Sm$_{1-x}$Gd$_x$Al$_2$ (x = 0.024) by combining polarized and unpolarized single crystal neutron diffraction data. The…
We discuss the random motion of charged test particles driven by quantum electromagnetic fluctuations at finite temperature in both the unbounded flat space and flat spacetime with a reflecting boundary and calculate the mean squared…