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arXiv · 2610.12791

Realizing Two-Dimensional Altermagnets with 100% Spin Polarization along the [110] Direction in Ambidentate-Ligand Based Square Organometallic Lattices

Qing-Bo Liu·Xin-Yi Chen·Xiangyang Li·Xingxing Li·Jinlong Yang
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Abstract

Altermagnetism, as a novel magnetic paradigm, not only possesses a zero net magnetic moment, but also exhibits a substantial nonrelativistic spin-splitting effect. Currently, developing a simple and experimentally feasible method for designing altermagnets is eagerly pursued. Moreover, achieving 100% spin polarization along certain directions in valence or conduction bands for altermagnets remains challenging. To address these issues, based on a tight-binding model, we propose a viable chemical strategy for constructing organometallic altermagnets by using ambidentate ligands. Furthermore, in these organometallic altermagnets, direction-dependent 100% spin polarization along the [110] direction in band edges can be induced via the coexistence of altermagnetically spin-split dispersive and flat bands, where the flat band suppresses electron transport in one spin channel and the dispersive band enables conduction in the other spin channel. Then, via first-principles calculations, a screening of 90 two-dimensional ambidentate-ligand based square organometallic lattices leads to the identification of three altermagnetic materials, namely Fe(taz)2Cl2 (taz = 1,2,4- triazine), Co(app)2Cl2, and Fe(app)2Cl2 (app = 1,4-azaphosphinine), all of which possess 100% spin polarization along the [110] direction in valence bands, as well as notable piezomagnetic behavior. This study paves the way for achieving direction-dependent fully spin-polarization in altermagnetic materials.

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Qing-Bo Liu, Xin-Yi Chen, Xiangyang Li, Xingxing Li, Jinlong Yang. 2026-10-12. Realizing Two-Dimensional Altermagnets with 100% Spin Polarization along the [110] Direction in Ambidentate-Ligand Based Square Organometallic Lattices. https://arxiv.org/abs/2610.12791

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