Evidence of Magnon-Mediated Orbital Magnetism in a Quasi-2D Topological Magnon Insulator

Abstract

We explore spin dynamics in Cu(1,3-bdc), a quasi-2D topological magnon insulator. The results show that the thermal evolution of Landé $g$-factor ($g$) is anisotropic: $g_{\text{in-plane}}$ reduces while $g_{\text{out-plane}}$ increases with increasing temperature $T$. Moreover, the anisotropy of the $g$-factor ($\Delta g$) and the anisotropy of saturation magnetization ($\Delta M_{\text{s}}$) are correlated below 4 K, but they diverge above 4 K. We show that the electronic orbital moment contributes to the $g$ anisotropy at lower $T$, while the topological orbital moment induced by thermally excited spin chirality dictates the $g$ anisotropy at higher $T$. Our work suggests an interplay among topology, spin chirality, and orbital magnetism in Cu(1,3-bdc).

6 pages, 4 figures

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Cited by in corpus (4)

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• Tunable magnon band topology and magnon orbital Nernst effect in noncollinear antiferromagnets
• Electric polarization induced by magnons and magnon Nernst effects