Fizika Nizkikh Temperatur: Volume 43, Number 12 (December 2017), p. 1715-1723    ( to contents , go back )

Spectra of collective excitations and the low-frequency asymptotic of Green’s functions of degenerate states of spin s = 1 magnets

A.V. Glushchenko, M.Y. Kovalevsky, and V.T. Matskevich

National Science Center “Kharkov Institute of Physics and Technology” 1 Akademicheskaya Str., Kharkov 61108, Ukrain
E-mail: glushchenko.ant@gmail.com, mik@kipt.kharkov.ua

Received June 19, 2017

Abstract

The paper describes the evolution of nonequilibrium degenerate states of one- and many-sublattice magnets with spin s = 1 in an external field. Dynamic equations for magnetic degrees of freedom have been obtained and low-frequency asymptotics of two-time Green's functions were calculated. The spectra of collective excitations in the states of a ferromagnet, a quadrupole magnet, and a spin nematic are found. A comparative analysis of these asymptotics is carried out and influence of the unitary symmetry of the exchange interaction on the character of the magnetic anisotropy is clarified.

PACS: 75.10.–b General theory and models of magnetic ordering.

Key words: spin, symmetry, dynamics, spectra of excitations, Green’s functions.

Published online: October 25, 2017

Download 320698 byte View Contents