Tunable Magnetic Antiskyrmion Size and Helical Period from Nanometers to Micrometers in a D_2d Heusler Compound

Abstract

Skyrmions and antiskyrmions are magnetic nano‐objects with distinct chiral, noncollinear spin textures that are found in various magnetic systems with crystal symmetries that give rise to specific Dzyaloshinskii–Moriya exchange vectors. These magnetic nano‐objects are associated with closely related helical spin textures that can form in the same material. The skyrmion size and the period of the helix are generally considered as being determined, in large part, by the ratio of the magnitude of the Heisenberg to that of the Dzyaloshinskii–Moriya exchange interaction. In this work, it is shown by real‐space magnetic imaging that the helix period λ and the size of the antiskyrmion daSk in the D2d compound Mn1.4PtSn can be systematically tuned by more than an order of magnitude from ≈100 nm to more than 1.1 µm by varying the thickness of the lamella in which they are observed. The chiral spin texture is verified to be preserved even up to micrometer‐thick layers. This extreme size tunability is shown to arise from long‐range magnetodipolar interactions, which typically play a much less important role for B20 skyrmions. This tunability in size makes antiskyrmions very attractive for technological applications.

Recent Progress in Exploring the Magnetic Solids with Room‐Temperature Skyrmionic Spin Configurations

“…[85] Recently, Ma et al discovered that the antiskyrmion size and helical period can be adjusted in single crystal Mn 1.4 PtSn from 100 nm to more than 1.1 μm by varying the thickness of the lamella from 116 nm to 4.2 μm (Figure 3c). [52] This size tunability is associated with longrange magnetodipolar interactions, and confirms that the spin texture can be maintained at the micron thickness of the sample.…”

“…However, this method cannot detect the internal topological features of magnetic vortices. [50][51][52] MOKE, which uses the polar magneto-optical Kerr effect, is an optical method to detect the magnetic characteristics of samples almost without incurring damage to them. This method is advantageous for detecting 2D magnetic materials and magnetic thin-film materials.…”

“…Reproduced under the terms of the Creative Commons CC-BY license. [52] Copyright 2020, The Authors. Published by Wiley-VCH and Sons.…”

Antiskyrmions and their electrical footprint in crystalline mesoscale structures

“…While experimental observations from, e.g., Lorentz transmission electron microscopy [6,25], neutron scattering [5] and magnetic force microscopy [26,27] have shown great advancement over the last decades, detection by electrical means is required for the realization of energy efficient spintronic devices [11,12], probabilistic [28] and neuromorphic computing [29]. Furthermore, a pivotal point for applications is the ability to control and scale skyrmionics [30,31], or even to transform one species of magnetic texture into another in multiskyrmion systems [24,32,33].…”

“…Most excitingly, an ASK lattice can be established at room temperature. Besides the high tunability of the Heusler compounds [27,32,35], the competition of magnetic exchange interactions and anisotropy lead to an enhanced temperature range over which ASKs can be stabilized in comparison to skyrmion bulk systems.…”