Witnessing topological spin textures in GdRu₂Ge₂ centrosymmetric magnet

Magnetic skyrmions are topologically protected spin swirls that are appreciated as a source of emergent electromagnetism. Their topological property and stable particle nature ensure skyrmion is a suitable candidate for low-power spin-based technologies. Particularly in centrosymmetric systems, magnetic skyrmions are mainly driven by long-range Ruderman-Kittel-Kasuya-Yosida (RKKY) exchange interactions assisted by geometrically frustrated lattice frameworks. One such goldmine for skyrmions in centrosymmetric systems is the Gd square lattice. GdRu₂Si₂ has recently been shown to host skyrmion lattice around T < 20 K and 2 T ≤ μ₀H ≤ 2.5 T.¹ Herein, we studied GdRu₂Ge₂ in order gain a deeper understanding of how increased spin-orbit coupling in the Ge analog influences the formation of skyrmions. Results from magnetoentropic mapping, topological Hall effect, and heat capacity measurements suggest the formation of skyrmions. We performed density functional theory calculations on both GdRu₂Ge₂ and GdRu₂Si₂ to connect and contrast the relationships between the spin-polarized band structures of these materials and their skyrmion evolution. In this presentation, we will share the knowledge gained from this research from both experimental and theoretical perspectives.

(1) Khanh, N. D.; Nakajima, T.; Yu, X.; Gao, S.; Shibata, K.; Hirschberger, M.; Yamasaki, Y.; Sagayama, H.; Nakao, H.; Peng, L. Nanometric square skyrmion lattice in a centrosymmetric tetragonal magnet. Nature Nanotechnology 2020, 15 (6), 444-449.