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arXiv · 2507.22996

Higher-order Topological States in Chiral Split Magnons of Honeycomb Altermagnets

Xuan Guo·Meng-Han Zhang·Dao-Xin Yao
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Abstract

We theoretically explore higher-order topological magnons in collinear altermagnets, encompassing a dimensional hierarchy ranging from localized corner modes to propagating hinge excitations. By employing antiferromagnetic interlayer coupling in bosonic Bogoliubov-de Gennes Hamiltonian, our work reveals anisotropic surface states and spatially distributed hinge modes propagating along facet intersections. We track the adiabatic evolution of Wannier centers to identify the bulk-polarization with second-order topological magnon insulator, where various magnon spectra demonstrate symmetry-protected band structure beyond conventional topology. Leveraging the stability and propagative properties of hinge modes, these unconventional magnons demonstrate manipulability in atomic-scale modifications of termination. Our study integrate altermagnetism with higher-order topology, which advance magnon-based quantum computing processing energy-efficient integrated architectures and information transfer.

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Xuan Guo, Meng-Han Zhang, Dao-Xin Yao. 2025-07-30. Higher-order Topological States in Chiral Split Magnons of Honeycomb Altermagnets. https://doi.org/10.1088/0256-307x%2F42%2F12%2F120703

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