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arXiv · 2308.16832

Magnon Orbital Angular Momentum of Ferromagnetic Honeycomb and Zig-Zag Lattices

R. S. Fishman·T. Berlijn·J. Villanova·L. Lindsay
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Abstract

By expanding the gauge $\lambda_n(k)$ for magnon band $n$ in harmonics of momentum ${\bf k} =(k,\phi )$, we demonstrate that the only observable component of the magnon orbital angular momentum $O_n({\bf k})$ is its angular average over all angles $\phi$, denoted by $F_n(k)$. For both the FM honeycomb and zig-zag lattices, we show that $F_n(k)$ is nonzero in the presence of a Dzyalloshinzkii-Moriya (DM) interaction. The FM zig-zag lattice model with exchange interactions $0 6$ but is still about four times smaller than that of the FM honeycomb lattice at high temperatures. Due to the removal of band degeneracies, $\kappa^{xy}(T)$ is slightly enhanced when $J_{1y}\ne J_{1x}$.

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R. S. Fishman, T. Berlijn, J. Villanova, L. Lindsay. 2023-08-31. Magnon Orbital Angular Momentum of Ferromagnetic Honeycomb and Zig-Zag Lattices. https://arxiv.org/abs/2308.16832

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