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Related papers: Statistical equilibrium measures in micromagnetics

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The mean-field thermodynamic limit is studied for a class of isolated Newtonian N-body systems whose Hamiltonian admits several invariants of motion. It is shown that the macrostates of individual members of a statistical equilibrium…

Mathematical Physics · Physics 2009-11-13 Michael K. -H. Kiessling

We introduce a stability criterion for quantum statistical ensembles describing macroscopic systems. An ensemble is called "stable" when a small number of local measurements cannot significantly modify the probability distribution of the…

Quantum Physics · Physics 2016-12-20 Walter Hahn , Boris V. Fine

We have performed realistic atomistic simulations at finite temperatures using Monte Carlo and atomistic spin dynamics simulations incorporating quantum (Bose-Einstein) statistics. The description is much improved at low temperatures…

Materials Science · Physics 2018-01-10 Lars Bergqvist , Anders Bergman

The Landau--Lifshitz equation describes the dynamics of magnetization inside a ferromagnet. This equation is nonlinear and has an infinite number of stable equilibria. It is desirable to control the system from one equilibrium to another. A…

Optimization and Control · Mathematics 2015-09-29 Amenda Chow , Kirsten A. Morris

A key feature of non-equilibrium thermodynamics is the Markovian, deterministic relaxation of coarse observables such as, for example, the temperature difference between two macroscopic objects which evolves independently of almost all…

Quantum Physics · Physics 2014-04-08 Hendrik Niemeyer , Kristel Michielsen , Hans de Raedt , Jochen Gemmer

The classical Landau--Lifshitz equation -- the simplest model of a ferromagnet -- provides an archetypal example for studying transport phenomena. In one-spatial dimension, integrability enables the classification of the spectrum of linear…

Statistical Mechanics · Physics 2024-09-06 Alvise Bastianello , Žiga Krajnik , Enej Ilievski

Atomistic spin model simulations are immensely useful in determining temperature dependent magnetic prop- erties, but are known to give the incorrect dependence of the magnetization on temperature compared to exper- iment owing to their…

Mesoscale and Nanoscale Physics · Physics 2015-05-12 R. F. L. Evans , U. Atxitia , R. W. Chantrell

Starting at the mesoscopic level with a general formulation of stochastic thermodynamics in terms of Markov jump processes, we identify the scaling conditions that ensure the emergence of a (typically nonlinear) deterministic dynamics and…

Statistical Mechanics · Physics 2025-05-26 Gianmaria Falasco , Massimiliano Esposito

Based on the view that thermal equilibrium should be characterized through macroscopic observations, we develop a general theory about typicality of thermal equilibrium and the approach to thermal equilibrium in macroscopic quantum systems.…

Statistical Mechanics · Physics 2018-08-02 Hal Tasaki

The present work is devoted to the derivation of an effective magnon-paramagnon theory starting from a microscopic lattice model of ferromagnetic metals. For some values of the microscopic parameters it reproduces the Heisenberg theory of…

Condensed Matter · Physics 2009-10-31 N. I. Karchev

Spin wave equations in the non-equilibrium precessing state of a ferromagnetic system are found. They show a spin-wave instability towards growing domains of stable magnetization. Precession of the uniform magnetization mode is described by…

Materials Science · Physics 2007-05-23 A. Kashuba

The dynamics of magnetisation in a bounded ferromagnet in $\mathbb{R}^d$ ($d=1,2$) at high temperatures can be described by the stochastic Landau--Lifshitz--Bloch (sLLB) equation, which is a vector-valued quasilinear stochastic partial…

Numerical Analysis · Mathematics 2026-02-23 Agus L. Soenjaya

We demonstrate the equilibration of isolated macroscopic quantum systems, prepared in non-equilibrium mixed states with significant population of many energy levels, and observed by instruments with a reasonably bound working range compared…

Statistical Mechanics · Physics 2009-11-13 Peter Reimann

We investigate the role of equilibrium and nonequilibrium noise in the magnetization dynamics on mono-domain ferromagnets. Starting from a microscopic model we present a detailed derivation of the spin shot noise correlator. We investigate…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 J. Swiebodzinski , A. Chudnovskiy , T. Dunn , A. Kamenev

We study fluctuations of pressure in equilibrium for classical particle systems. In equilibrium statistical mechanics, pressure for a microscopic state is defined by the derivative of a thermodynamic function or, more mechanically, through…

Statistical Mechanics · Physics 2018-10-05 Ken Hiura , Shin-ichi Sasa

Unlike macroscopic multistable mechanical systems such as snap bracelets or elastic shells that must be physically manipulated into various conformations, microscopic systems can undergo spontaneous conformation switching between…

Statistical Mechanics · Physics 2013-08-29 Ee Hou Yong , L. Mahadevan

A simplified model is introduced and analysed to show, that for the Landau-Lifshitz equation stable, steady state solutions of domain type exist in ferromagnetic systems, strongly driven by external transverse fields. These dynamic domain…

Condensed Matter · Physics 2007-05-23 T. Plefka

We present a micromagnetic formulation for modeling the magnetization dynamics and thermal equilibrium in ferrimagnetic materials at low and elevated temperatures. The formulation is based on a mean field approximation (MFA). In this…

Materials Science · Physics 2021-11-30 Marco Menarini , Vitaliy Lomakin

Combining wide-field magneto-optical Kerr microscopy with a time-lapse analysis scheme allows investigating magnetization fluctuations with high spatial as well as temporal resolution. We here use this technique to study magnetization…

In the present paper, recent experimental results on large scale coherent steady states observed in experimental von K{\'a}rm{\'a}n flows are revisited from a statistical mechanics perspective. The latter is rooted on two levels of…