Magnetic Skyrmions with Unconventional Helicity Polarization in a Van Der Waals Ferromagnet

Magnetic Skyrmions with Unconventional Helicity Polarization in a Van Der Waals Ferromagnet

© 2022 Wiley-VCH GmbH.

Détails bibliographiques
Publié dans:Advanced materials (Deerfield Beach, Fla.). - 1998. - 34(2022), 42 vom: 12. Okt., Seite e2204163
Auteur principal: Zhang, Chenhui (Auteur)
Autres auteurs: Liu, Chen, Zhang, Senfu, Zhou, Bojian, Guan, Chaoshuai, Ma, Yinchang, Algaidi, Hanin, Zheng, Dongxing, Li, Yan, He, Xin, Zhang, Junwei, Li, Peng, Hou, Zhipeng, Yin, Gen, Liu, Kai, Peng, Yong, Zhang, Xi-Xiang
Format: Article en ligne
Langue:English
Publié: 2022
Accès à la collection:Advanced materials (Deerfield Beach, Fla.)
Sujets:Journal Article Dzyaloshinskii-Moriya interaction helicity magnetic skyrmions perpendicular magnetic anisotropy van der Waals materials
Description
Résumé:© 2022 Wiley-VCH GmbH.
Skyrmion helicity, which defines the spin swirling direction, is a fundamental parameter that may be utilized to encode data bits in future memory devices. Generally, in centrosymmetric ferromagnets, dipole skyrmions with helicity of -π/2 and π/2 are degenerate in energy, leading to equal populations of both helicities. On the other hand, in chiral materials where the Dzyaloshinskii-Moriya interaction (DMI) prevails and the dipolar interaction is negligible, only a preferred helicity is selected by the type of DMI. However, whether there is a rigid boundary between these two regimes remains an open question. Herein, the observation of dipole skyrmions with unconventional helicity polarization in a van der Waals ferromagnet, Fe5- δ GeTe2 , is reported. Combining magnetometry, Lorentz transmission electron microscopy, electrical transport measurements, and micromagnetic simulations, the short-range superstructures in Fe5- δ GeTe2 resulting in a localized DMI contribution, which breaks the degeneracy of the opposite helicities and leads to the helicity polarization, is demonstrated. Therefore, the helicity feature in Fe5- δ GeTe2 is controlled by both the dipolar interaction and DMI that the former leads to Bloch-type skyrmions with helicity of ±π/2 whereas the latter breaks the helicity degeneracy. This work provides new insights into the skyrmion topology in van der Waals materials
Description:Date Revised 20.10.2022
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1521-4095
DOI:10.1002/adma.202204163