Fizika Nizkikh Temperatur: Volume 44, Number 7 (July 2018), p. 794-813    ( to contents , go back )

Dynamic solitons in antiferromagnets (Review Article)

E.G. Galkina

Institute of Physics of the National Academy of Sciences 46 Nauki Ave., Kiev 03028, Ukraine

B.A. Ivanov

Institute of Magnetism, NASU, 36-B Vernadskii Ave., Kiev 03142, Ukraine
E-mail: bor.a.ivanov@gmail.com

Received March 1, 2018

Abstract

The review of theoretical studies of magnetic solitons in antiferromagnets (AFM) is presented. The basic concepts of the physics AFM and of the soliton theory are given. An analysis of the nonlinear dynamics of an AFM is carried out on the unified ground with the use of a nonlinear sigma model for the antiferromagnetic vector. The derivation of this equation and its integrals of motion are discussed with accounting for the real structure of the AFM. The main attention is paid to the study of two-parametrical solitons, which are cha-acterized by both the translational motion of the soliton center and the internal dynamics of spins inside the soliton. Solitons of various types, one-dimensional and two-dimensional, topological and not possessing a topological charge, are considered. An analysis of the effects of the lowering of the dynamic symmetry of the AFM, which are due to the destruction of the Lorentz-invariant character of the sigma model, is made. Such effects arise when the Dzyaloshinsky–Moriya interaction and/or the strong external magnetic field are accounted for consistently. The last problem was never discussed in monographic literature. The classes of universality for the behavior of moving solitons are established.

PACS: 75.50.Ee Antiferromagnetics;
PACS: 75.76.+j Spin transport effects;
PACS: 75.78.–n Magnetization dynamics.

Key words: antiferromagnets, antiferromagnetic vector, nonlinear sigma model, Dzyaloshinsky–Moriya interaction, domain wall, AFM vortex, droplet soliton, skyrmion, terahertz magnons, spintronics, spin-torque oscillator.

Published online: May 28, 2018

Download 684449 byte View Contents