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arXiv · 2503.18649

Phenomenological Ginzburg-Landau theory for triple-Q magnetic orders on a hexagonal lattice

Jin-Tao Jin·Yi Zhou
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Abstract

We develop a comprehensive Ginzburg-Landau theory describing triple-Q magnetic orders on hexagonal lattices, focusing on $O(N)$ models with $N=2$ and $N=3$. Through systematic analysis of symmetry-allowed terms in the free energy, we establish complete phase diagrams governed by competing interaction parameters. Our theory reveals distinct magnetic configurations including single-Q, double-Q, and triple-Q states, each characterized by unique symmetry breaking patterns and collective excitations. The framework provides fundamental insights into complex magnetic orders recently observed in materials such as Na$_2$Co$_2$TeO$_6$, where the interplay between geometric frustration and multiple ordering vectors leads to exotic magnetic states. Our results establish clear connections between microscopic interactions, broken symmetries, and experimentally observable properties, offering a powerful tool for understanding and predicting novel magnetic phases in frustrated magnets.

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Jin-Tao Jin, Yi Zhou. 2025-03-24. Phenomenological Ginzburg-Landau theory for triple-Q magnetic orders on a hexagonal lattice. https://doi.org/10.1103/nvnm-rtwd

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