Programme

O.7 -- Oral, ANSWCCMS-2023

Date: Friday, 10 November 2023

Time: 14:00 - 14:30

Mean-field description of skyrmion phases in frustrated antiferromagnets

Oleg Utesov

Center for Theoretical Physics of Complex Systems, Institute for Basic Science, Daejeon, Korea

Magnetic skyrmions and their ordered arrays - skyrmion lattices (SkL) - are extensively studied in the present time. Importantly, topologically nontrivial spin structures are promising from a technological point of view. For example, they can be used in racetrack memory or in unconventional computing. From the theoretical perspective, topological SkL phases stabilization is usually ascribed to the subtle interplay between various magnetic interactions, e.g., exchange coupling, Dzyaloshinskii-Moriya antisymmetric exchange, Zeeman energy, and anisotropic terms. Moreover, the importance of thermodynamic fluctuations is often highlighted. At low temperatures, SkL can be constructed as an ordered array of isolated skyrmions with a certain interaction potential and subsequent numerical energy optimization. This approach also allows to study of elementary excitations of SkL. In the present study, it is shown that in frustrated antiferromagnets on tetragonal and hexagonal lattices, SkL phases appear in a simple model that takes into account magnetodipolar interaction [1,2]. It is argued that in the framework of the mean-field approach, dipolar forces stabilize lattices of Bloch-type skyrmions in certain regions of high-temperature phase diagrams. Furthermore, the corresponding phase boundaries can be derived analytically. Several types of generic phase diagrams are proposed and their connection with experiments on tetragonal GdRu2Si2 and hexagonal Gd2PdSi3 skyrmion hosts is discussed. [1] Oleg Utesov, Phys. Rev. B 103, 064414 (2021). [2] Oleg Utesov, Phys. Rev. B 105, 054435 (2022).

Presenter: Oleg Utesov

Presentation file: