DOI: https://doi.org/10.30970/jps.02.123
DYNAMIC AND TOPOLOGIC SOLITONS IN QUASI-ONE-DIMENSIONAL FERROMAGNETIC SYSTEMS
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Journal of Physical Studies 2(1), 123–127 (1998)
DOI: https://doi.org/10.30970/jps.02.123 DYNAMIC AND TOPOLOGIC SOLITONS IN QUASI-ONE-DIMENSIONAL FERROMAGNETIC SYSTEMS |
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V. Yatsyshyn
Ivan Franko Drohobych State Pedagogical Institute
24 I. Franko Str., UA-293720, Drohobych, Ukraine
A one-dimensional ferromagnetic anisotropic chain with regard for the lattice fluctuations in harmonic approximation is investigated. Anisotropy is caused by exchange interaction anisotropy. Using the quantum approach one-particle wall excitations are considered. It is shown that the wave function of these excitations satisfies the Schrödinger nonlinear equation. The nonlinearity of the latter which is caused by the chain dynamics is possible for anisotropic ferromagnetic systems only. Here lies the importance of anisotropy.
The solution of the Schrödinger nonlinear equation reveals the wave function to be of a localized nature and the fundamental state energy of the corresponding excitations (which we call magnetic solitons) to be lower than the energy of ordinary magnons.
The influence of unharmonicity of lattice fluctuations on the parameters of magnetic solitons is determined.
Together with the dynamic solitons the influence of lattice fluctuations on the parameters of topologic solitons of domain walls type is considered. The domain walls width and the partial constituent of the width caused by the lattice dynamics are determined. It turned out that the wave speed limiting appears if fluctuations are regarded as ordinary waves. The corresponding top wave speed is calculated.