Low Temperature Physics: 36, 802 (2010); https://doi.org/10.1063/1.3493408 (6 pages)
Fizika Nizkikh Temperatur: Volume 36, Number 8-9 (August 2010), p. 1006-1012 ( to contents , go back )
Dynamics of normal and degenerate nonequilibrium states of magnets with spin S = 1
National Science Center "Kharkov Institute of Physics and Technology" 1 Academicheskaya St., Kharkov 61108, Ukraine
Received December 28, 2009
Using the variation principle the Poisson brackets for the whole set of macroscopic parameters are obtained and nonlinear dynamic equations of magnetic media with spin S = 1 for normal and degenerate states are derived. Two types of exchange magnetic Hamiltonians corresponding to two Kazimir invariants of SU(3) group are introduced in consideration. A thermodynamics of magnets investigated is constructed and flux densities of additive integrals of motion in terms of energy density are found. A magnon momentum in the condensed matter under consideration is introduced and its dynamic equation is derived. Spectra of spin and quadrupole waves for various time symmetry of equilibrium states obtained are.
PACS: 75.10.–b General theory and models of magnetic ordering.
Key words: magnets, Hamiltonian approach, Poisson brackets, conservation laws, Landau-Lifshitz equation, spin wave spectrum.