Intrinsic stability of magnetic anti-skyrmions in the tetragonal inverse Heusler compound Mn1.4Pt0.9Pd0.1Sn

Rana Saha,Peter Werner,Abhay K Srivastava,Claudia Felser,Tianping Ma,Stuart S P Parkin,Vivek Kumar,Jagannath Jena

doi:10.1038/s41467-019-13323-x

Abstract

Magnetic anti-skyrmions are one of several chiral spin textures that are of great current interest both for their topological characteristics and potential spintronic applications. Anti-skyrmions were recently observed in the inverse tetragonal Heusler material Mn1.4Pt0.9Pd0.1Sn. Here we show, using Lorentz transmission electron microscopy, that anti-skyrmions are found over a wide range of temperature and magnetic fields in wedged lamellae formed from single crystals of Mn1.4Pt0.9Pd0.1Sn for thicknesses ranging up to ~250 nm. The temperature-field stability window of the anti-skyrmions varies little with thickness. Using micromagnetic simulations we show that this intrinsic stability of anti-skyrmions can be accounted for by the symmetry of the crystal lattice which is imposed on that of the Dzyaloshinskii-Moriya exchange interaction. These distinctive behaviors of anti-skyrmions makes them particularly attractive for spintronic applications.

Highlights

Magnetic anti-skyrmions are one of several chiral spin textures that are of great current interest both for their topological characteristics and potential spintronic applications
In the latter system it is clear that there will be a strong dependence of the Sk phase on the multilayer thickness, the situation for Sks and aSks stabilized by bulk Dzyaloshinskii-Moriya exchange interaction (DMI) is less certain
Studies were prepared from single crystal grains within bulk polycrystalline Mn1.4Pt0.9Pd0.1Sn using focused ion-beam milling (FIB). [001] oriented grains were identified by electron backscattering diffraction

Summary

Introduction

Magnetic anti-skyrmions are one of several chiral spin textures that are of great current interest both for their topological characteristics and potential spintronic applications. Using micromagnetic simulations we show that this intrinsic stability of anti-skyrmions can be accounted for by the symmetry of the crystal lattice which is imposed on that of the Dzyaloshinskii-Moriya exchange interaction These distinctive behaviors of anti-skyrmions makes them attractive for spintronic applications. Magnetic skyrmions (Sks) and anti-skyrmions (aSks) are topologically protected nanoscopic magnetic entities that can be stabilized in magnetic materials with broken inversion symmetry1–6 These innately chiral magnetic objects have been proposed as candidates for high-density racetrack memory, neuromorphic computing applications, and logic components. Néel Sk bubbles have been observed in magnetic multilayers via an interface DMI18 In the latter system it is clear that there will be a strong dependence of the Sk phase on the multilayer thickness, the situation for Sks and aSks stabilized by bulk DMI is less certain. Using micromagnetic simulations we compare the thickness-field dependent phase diagrams of cubic and D2d systems that clearly shows the intrinsic stability of anti-skyrmions in the latter systems

Methods

Results

Conclusion