2024/04/04 by Quentin Faure, A. Toschi, Faure, Q. +13
Physics and Astronomy · Materials Science · #Advanced Condensed Matter Physics #Nuclear materials and radiation effects
paper · pdf · doi:10.48550/arxiv.2404.03829
We report a resonant inelastic X-ray scattering study on a single crystal of a non-stoichiometric pyrochlore iridate Tb2+xIr2-xO7-y (x ≃ 0.25) that magnetically orders at T_\rmN≃ 50 K. We find that the strength of the spin-orbit coupling and the trigonal distortion of the IrO6 octahedra are comparable with the ones obtained in other pyrochlore iridates. We observe a propagating gapped magnon mode at low energy, and model it using a Hamiltonian consisting of a Heisenberg exchange [J = 16.2(9) meV] and Dzyaloshinskii-Moriya interactions [D = 5.2(3) meV], which shows the robustness of interactions despite Tb-stuffing at the Ir-site. Strikingly, the ratio D/J = 0.32(3) supports possible non-trivial topological magnon band crossing. This material may thus host coexisting fermionic and bosonic topology, with potential for manipulating electronic and magnonic topological bands thanks to the d-f interaction.