Defect Geometry Selects Polar and Anomalous Hall Phases in Two-Dimensional Altermagnets

Xujia Gong; Amar Fakhredine; Hosein Alavi-Rad; Mahyar Hassani-Vasmejani; Xing Ming; Xiangang Wan; Carmine Autieri; Meysam Bagheri Tagani; Sahar Izadi Vishkayi

arXiv · 2608.17788

Defect Geometry Selects Polar and Anomalous Hall Phases in Two-Dimensional Altermagnets

Xujia Gong·Amar Fakhredine·Hosein Alavi-Rad·Mahyar Hassani-Vasmejani·Xing Ming·Xiangang Wan·Carmine Autieri·Meysam Bagheri Tagani·Sahar Izadi Vishkayi

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Abstract

Point defects in altermagnets can create phases absent in the pristine host by selectively breaking crystal symmetries. Combining symmetry analysis, first-principles calculations, and Hamiltonian modeling, we identify how point impurities modify the altermagnetic phase. Using the pristine d- wave altermagnetic monolayer V2Se2O as a testbed, we identify three distinct classes of impurities: those that preserve spin-momentum locking, those that induce a hybrid-parity state associated with Edelstein spin conversion, and those that produce a metallic ferrimagnetic state with an anomalous Hall effect. We further discuss the robustness of two-dimensional altermagnets against point impurities. Results for other two-dimensional systems, such as Mn4N2 and 2H-FeBr3, reveal the same symmetry-based control across distinct lattices and parent spin harmonics, establishing defect geometry as a general route for engineering spin textures and transport properties.

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Xujia Gong, Amar Fakhredine, Hosein Alavi-Rad, Mahyar Hassani-Vasmejani, Xing Ming, Xiangang Wan, Carmine Autieri, Meysam Bagheri Tagani, Sahar Izadi Vishkayi. 2026-08-18. Defect Geometry Selects Polar and Anomalous Hall Phases in Two-Dimensional Altermagnets. https://arxiv.org/abs/2608.17788

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