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arXiv · 2604.04574

Broken Symmetry-driven Weyl Semimetal Phase in Zn-Substituted EuMn$_2$Sb$_2$

Deep Sagar·Arti Kashyap
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Abstract

The interplay between magnetism and electronic topology offers a powerful route to realizing emergent quantum phases. Here, we show that Zn substitution in the layered compound EuMn$_2$Sb$_2$ drives a transition from a C-type antiferromagnetic semiconductor to an intrinsic magnetic Weyl semimetal. Using first-principles calculations, we demonstrate that the parent compound hosts a gapped antiferromagnetic ground state, while Zn substitution alters the magnetic exchange interactions and stabilizes ferromagnetism. In the spin-orbit-coupled regime, the coexistence of broken time-reversal ($\mathcal{T}$) and inversion ($\mathcal{P}$) symmetries leads to the formation of Weyl nodes near the Fermi level. These nodes act as monopoles of Berry curvature and give rise to topologically protected Fermi-arc surface states. Our results identify EuMnZnSb$_2$ as a tunable platform where magnetism and topology are intrinsically coupled and establish chemical substitution as a viable strategy to engineer magnetic Weyl semimetals in correlated electron systems, with potential implications for spintronic and topological transport phenomena.

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Deep Sagar, Arti Kashyap. 2026-04-06. Broken Symmetry-driven Weyl Semimetal Phase in Zn-Substituted EuMn$_2$Sb$_2$. https://arxiv.org/abs/2604.04574

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