Magnetoelectric Properties and Symmetry Classification of Micromagnetic Structures

Abstract: The magnetoelectric (ME) effects are caused by interactions of the electrical and magnetic subsystems in a solid. Among the applications of ME effects, there are methods of magnetic reversal under the influence of an electrostatic field and the reverse effect. As a result of the theoretical studies carried out in this thesis, we obtained a complete symmetry classification of all the main micromagnetic structures (domain walls, Bloch lines, Bloch points, and magnetic vortices/skyrmions), where the structures were first divided by their magnetic chirality. The organic connection of this classification with the inhomogeneous magnetoelectric effects in them has been shown. The inhomogeneous ME effect is qualitatively described for each symmetry class. Additionally, the known phenomenological theory of these effects is extended to the cases of crystals of cubic, tetragonal, and orthorhombic systems. The obtained results were analyzed for their compatibility with the existing experimental facts, and the possibility of detecting new phenomena has been suggested.