A magnon band analysis of GdRu2Si2 in the field-polarized state

• Published in: npj Quantum Materials
• Main Authors: G. D. A. Wood, J. R. Stewart, D. A. Mayoh, J. A. M. Paddison, J. Bouaziz, S. M. Tobin, O. A. Petrenko, M. R. Lees, P. Manuel, J. B. Staunton, G. Balakrishnan
• Format: Article
• Language: English
• Published: Nature Portfolio 2025-04-01
• Online Access: https://doi.org/10.1038/s41535-025-00755-6

Abstract Understanding the formation of skyrmions in centrosymmetric materials is a problem of fundamental and technological interest. GdRu2Si2 is a candidate material that hosts a variety of multi-Q magnetic phases, including in zero-field. Here, inelastic neutron scattering is used to measure the spin excitations in the field-polarized phase of GdRu2Si2. Linear spin wave theory and a method of interaction invariant path analysis are used to derive a Hamiltonian accounting for the spectra. The Hamiltonian, dominated by bilinear (Ruderman-Kittel-Kasuya-Yosida) Heisenberg exchange, compares favorably to ab initio calculations. Dipolar interactions are a secondary energy scale to consider, with J D.D~ 0.05J RKKY. However, it is shown that in the field-polarized phase the dipolar interactions ‘self screen’ so that their effect is largely suppressed. No specific evidence for higher-order exchange is found. These aspects are discussed in the context of the lower field multi-Q states and the anisotropy of the system.