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arXiv · 2107.11484

Dzyaloshinskii-Moriya Induced Topological Magnon-Phonon Hybridization in 2D Antiferromagnetic Insulators with Tunable Chern Numbers

Bowen Ma·Gregory A. Fiete
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Abstract

We theoretically study magnon-phonon hybrid excitations (magnon-polarons) in two-dimensional antiferromagnets on a honeycomb lattice. With an in-plane Dzyaloshinskii-Moriya interaction (DMI) allowed from mirror symmetry breaking from phonons, we find non-trivial Berry curvature around the anti-crossing rings among magnon and both optical and acoustic phonon bands, which gives rise to finite Chern numbers. We show that the Chern numbers of the magnon-polaron bands can be manipulated by changing the magnetic field direction or strength. We evaluate the thermal Hall conductivity reflecting the non-trivial Berry curvatures of magnon-polarons and propose a valley Hall effect resulting from spin-induced chiral phonons as a possible experimental signature. Our study complements prior work on magnon-phonon hybridized systems without optical phonons and suggests possible applications in spin caloritronics with topological magnons and chiral phonons.

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Bowen Ma, Gregory A. Fiete. 2021-07-23. Dzyaloshinskii-Moriya Induced Topological Magnon-Phonon Hybridization in 2D Antiferromagnetic Insulators with Tunable Chern Numbers. https://doi.org/10.1103/physrevb.105.l100402

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