Field-orientation-dependent magnetic phases in GdRu2⁢Si2 probed with muon-spin spectroscopy

Journal article

Centrosymmetric GdRu2⁢Si2 exhibits a variety of multi-𝑄 magnetic states as a function of temperature and applied magnetic field, including a square skyrmion-lattice phase. The material's behavior is strongly dependent on the direction of the applied field, with different phase diagrams resulting for fields applied parallel or perpendicular to the crystallographic 𝑐 axis. Here, we present the results of muon-spin relaxation (𝜇+⁢SR) measurements on single crystals of GdRu2⁢Si2. Our analysis is based on the computation of muon stopping sites and consideration of quantum zero-point motion effects of muons, allowing direct comparison with the underlying spin textures in the material. The muon site is confirmed experimentally, using angle-dependent measurements of the muon Knight shift. Using transverse-field 𝜇+⁢SR with fields applied along either the [001] or [100] crystallographic directions, we distinguish between the magnetic phases in this system via their distinct muon response, providing additional evidence for the skyrmion and meron-lattice phases, while also suggesting the existence of RKKY-driven muon hyperfine coupling. Zero-field 𝜇+⁢SR provides clear evidence for a transition between two distinct magnetically ordered phases at 39 K.

Authors: Huddart, BM; Hernández-Melián, A; Wood, GDA; Mayoh, DA; Gomilšek, M

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Physical Society
• Journal: Physical Review B
• Volume: 111
• Issue: 5
• Article number: 54440
• Publication date: 2025-02-27
• Acceptance date: 2025-01-29
• DOI: 10.1103/physrevb.111.054440
• EISSN: 2469-9969
• ISSN: 2469-9950
• Language: English