Control of chaotic and deterministic magnetization dynamics regimes by means of sample shape varying

Abstract

Effect of demagnetization field on chaotic and deterministic nonlinear magnetization dynamics regimes formation in the presence of oscillating and constant external magnetic fields is studied using the Landau–Lifshitz–Gilbert approach. The uniformly magnetized sample is considered to be an axially symmetric particle described by demagnetization factors and to have uniaxial crystallographic anisotropy formed some angle with an applied field direction. The equations of magnetic moment motion are considered to be the synergetic equations and the system behavior is examined on the phase plane. It is investigated as to how the change in particle shape and its orientation with respect to the external field (system’s configuration) can cause the transition between chaos and regular magnetization dynamics. Moreover, the way to completely suppress chaotic dynamics of magnetic moments in such sample is proposed. To produce a regular study, all results are presented in the form of bifurcation diagrams for all sufficient dynamics regimes of the considered system. Our results suggest that varying the particle’s shape and fields’ geometry may provide a useful way of magnetization dynamics control in complex magnetic systems.

Energy dissipation in single-domain ferromagnetic nanoparticles: Dynamical approach

“…In particular, the regimes of quasiperiodic [25] and chaotic [29][30][31] motion of m can be realized in circularly and linearly polarized magnetic fields, respectively. Therefore, to find the power loss in these and other cases, Eqs.…”

“…In particular, the circularly polarized magnetic field, whose polarization plane is perpendicular to the anisotropy axis, can generate the periodic and quasiperiodic regimes of * lyutyy@oeph.sumdu.edu.ua † denisov@sumdu.edu.ua precession of the magnetic moment [25][26][27][28]. Moreover, the precessional motion of the magnetic moment induced by the linearly polarized magnet field can exhibit chaotic behavior [29][30][31].…”

Hyper-chaotic Magnetisation Dynamics of Two Interacting Dipoles

“…Apart from the Lyapunov spectrum analysis, there are other methods of quantifying the dynamical behaviour of a system, such as the Fourier spectrum, Poincaré sections, or correlation functions, just to mention few [10,12,17,41]. The classical technique to understand the time series of each component of m i is to take the Fast Fourier Transform (FFT) which gives a complex discrete signal, S (ϖ), in the frequency space ϖ = (ϖ 1 , ..., ϖ n ), producing a set of pairs {ϖ k , S (ϖ k )}.…”

“…The standard approach to study the magnetisation dynamics is based on the LandauLifshitz system, which was derived 80 years ago [11]. Using this model (or its generalisations), theoretical descriptions and phase diagrams of the chaotic regions have been given and explored [12,13,14,15,16,17,18,19,20,21,22]. Some of these models show new possible roots and ranges of physical parameters in chaotic domains that could motivate new experiments in this area.…”

Classical spin dynamics of anisotropic Heisenberg dimmers

“…[16,17]. These models have been used in discrete [17][18][19][20][21][22] and continuous magnetic systems [17,[23][24][25][26][27][28][29][30]. The dynamical behavior of a few magnetic particles interacting through an exchange interaction were studied in Refs.…”