Searching for magnetic skyrmion in noncentrosymmetric EuPtAs

by Wu Xie (FS-PETRA-S (FS-PET-S Fachgruppe P09))

Tuesday 1 Nov 2022, 13:15 → 14:00 Europe/Berlin

Online

Magnetic systems lacking inversion symmetry and with significant spin-orbit coupling can exhibit the antisymmetric Dzyaloshinskii-Moriya (DM) interaction between magnetic moments, in addition to Heisenberg-typed exchange interactions. The DM interaction can give rise to a number of non-collinear magnetic ground states, such as helical magnetic structures, which may be transformed to magnetic skyrmion phases under applied magnetic field, as realized in some chiral B20 compounds, such as MnSi [1,2]. More recently, a similar field-temperature magnetic phase diagram has been reported in EuPtSi, in which there is also a magnetic skyrmion phase [3] with different characteristics to that of MnSi. Such observations have stimulated a surge of research interest in search of skyrmion-like topological spin texture (TST) in rare-earth based compounds [4].

Here we focus on noncentrosymmetric polar magnet EuPtAs. Starting from the synthesis of both poly- and single- crystals, we have comprehensively characterized the basic physical properties of EuPtAs at temperatures down to 1.9 K, leading to constructed temperature--magnetic field phase diagrams.  To solve the magnetic structures, both neutron scattering and resonant x-ray magnetic scattering techniques are utilized. Our studies reveal complex spin textures in EuPtAs, with potential existence of magnetic skrymion (or other TSTs) under magnetic fields.

[1] Nagaosa and Y. Tokura, Nat. Nanotechnol. 8, 899 (2013);

[2] S. Mühlbauer et al., Science 323, 915 (2009);

[3] C. Tabata, et al., J. Phys. Soc. Jpn. 88, 013702 (2019);

[4] T. Kurumaji, et al., Science 365, 914 (2019); Nat. Commun. 10, 5831 (2019).