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arXiv · 2412.04593

Spin Chern number in altermagnets

Rafael Gonzalez-Hernandez·Higinio Serrano·Bernardo Uribe
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Abstract

This work explores the topological properties of altermagnets, a novel class of collinear magnetic materials. We employ equivariant K-theory of magnetic groups and Hamiltonian models to formulate a robust $C^z_4 \mathbb{T}$ topological invariant to classify 2D and 3D altermagnetic systems. Our findings demonstrate that the spin Chern number serves as a robust topological index, corresponding to the half-quantized Chern number of the divided Brillouin zone. This indicator enables the prediction of a topologically protected 2D altermagnetic insulators and 3D Weyl altermagnetic semimetals, highlighting the relationship between altermagnetism and topological phases. Furthermore, our results provide a pathway to the exploration of topological applications in $d$-wave altermagnetic materials.

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Rafael Gonzalez-Hernandez, Higinio Serrano, Bernardo Uribe. 2024-12-05. Spin Chern number in altermagnets. https://doi.org/10.1103/physrevb.111.085127

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