Non-collinear Spin Textures in Heusler Compounds

Recently, non-collinear spin textures such as skyrmions have attracted significant attention due to their topological nature, emergent electromagnetic properties, and potential spintronics device applications1-3. Skyrmions are formed in a compound with broken inversion symmetry and spin-orbit-coupling, inducing the Dzyaloshinskii-Moriya interaction (DMI). Although there have been many studies on B20 and Cnv systems, which produce Bloch and Néel skyrmions, the investigation of spin textures on D2d compounds is fairly new4. In this talk, I will present the formation and properties of several new and unexpected spin textures, namely elliptical Bloch skyrmions, fractional (anti)skyrmions, and square-shaped antiskyrmions in the D2d Heusler compounds Mn1.4Pt0.9Pd0.1Sn and Mn2Rh0.95Ir0.05Sn5-9. We showed that these could be understood by a combination of dipole-dipole interactions and a chiral vector exchange that makes it possible to observe various spin textures in even the same compound. From these studies, we have gained a significant fundamental understanding of these interesting chiral magnetic nano-objects, which have the potential for spintronic applications. At the end of the talk, I will discuss the magnetic and transport properties of thin-film Heusler compounds grown by molecular beam epitaxy and sputtering deposition8,10.

References:
1. Nagaosa, N. et al., Topological properties and dynamics of magnetic skyrmions. Nat. Nanotechnol. 8, 899 (2013).
2. Parkin, S. S. P. et al., Memory on the racetrack. Nat. Nanotechnol. 10, 195 (2015).
3. Fert, A. et al., Skyrmions on the track. Nat. Nanotechnol. 8, 152 (2013).
4. Nayak, A. K., et al., Magnetic antiskyrmions above room temperature in tetragonal Heusler materials. Nature 548, 561 (2017).
5. Jena, J., et al., Observation of magnetic antiskyrmions in the low magnetization ferrimagnet Mn2Rh0. 95Ir0. 05Sn. Nano Lett. 20, 59 (2020).
6. Jena, J., et al., Elliptical Bloch skyrmion chiral twins in an antiskyrmion system. Nat. Commun. 11, 1115 (2020).
7. Jena, J., et al., Evolution and competition between chiral spin textures in nanostripes with D2d symmetry. Sci. Adv. 6, eabc0723 (2020).
8. Sharma, A., Jena, J. et al., Nanoscale noncollinear spin textures in thin films of a Heusler compoundAdv. Mater. 32, 2101323 (2021).
9. Jena, J., et al., Observation of fractional spin textures in a Heusler material. Nat. Commun. 13, 12348 (2022).
10. Jena, J., et al., Nano-scale Néel-type spin textures in epitaxial acentric Heusler PtMnGa thin films. Manuscript in preparation, xx, xxxx, (2023).