Stability of skyrmion formation and its abnormal dynamic modes in magnetic nanotubes

Author(s)
Jaehak Yang, Junhoe Kim, Claas Abert, Dieter Suess, Sang-Koog Kim
Abstract

We studied the stability of skyrmion formation and its abnormal dynamic motions in magnetic nanotubes with perpendicular magnetic anisotropy with respect to the tube surface. Unlike planar geometry, skyrmions, which are formed in an elliptical shape, are stabilized, to a greater or lesser degree, by the curved geometry, depending on the sign of the Dzyaloshinskii-Moriya Interaction (DMI) constant. The positive and negative signs of the DMI constant play a crucial role in the formation of skyrmions on the curved surface. These effects become stronger as the diameter of the tube decreases, quantitatively evidencing that the curvature-induced DM-like interaction also contributes to the stability of skyrmion formation. The dynamic modes of the skyrmion in the tubes are found to be as follows: two in-plane gyration modes in the counterclockwise (CCW) and clockwise (CW) rotation senses, and one out-of-plane breathing mode. On the other hand, in contrast to the planar geometry, the initial CCW gyration motion turns out to be a linear translational motion in the circumferential direction of the tube for cases where the strength of axial AC magnetic fields is greater than a threshold field strength. The direction of the translational motions is determined by the skyrmion helicity governed by the sign of the interfacial DMI constant. This work provides further physical insight into the static and dynamic properties of skyrmions formed in curved-geometry systems and also suggests its potential application to information processing devices.

Organisation(s)
Research Platform MMM Mathematics-Magnetism-Materials, Physics of Functional Materials
External organisation(s)
Seoul National University (SNU)
Journal
Physical Review B
Volume
102
No. of pages
9
ISSN
2469-9950
DOI
https://doi.org/10.1103/PhysRevB.102.094439
Publication date
09-2020
Peer reviewed
Yes
Austrian Fields of Science 2012
103018 Materials physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/stability-of-skyrmion-formation-and-its-abnormal-dynamic-modes-in-magnetic-nanotubes(16a5e215-2f92-4af0-afbc-1484de97176a).html