Altermagnetism of ultrathin CrSb slabs

Altermagnets exhibit momentum-dependent spin splitting without net magnetization, combining characteristics of both ferromagnets and antiferromagnets, making them highly interesting for spintronics applications. CrSb is a prime candidate with a high Néel temperature ( ∼ 700 K ) and a large exchange-driven splitting of ∼ 0.6 – 1 eV . Using calculations, we consider slabs of various orientations in the ultrathin limit. In (0001)-oriented slabs, the exchange-driven altermagnetic spin splitting collapses, but including spin-orbit coupling restores a residual anisotropic splitting of ∼ 70 meV . The (100)-oriented slabs become fully spin degenerate due to symmetry reduction. In contrast, the (110)-oriented slabs show a strong altermagnetic spin splitting of ∼ 400 meV , and thus emerges as a robust candidate for realizing large, exchange-driven altermagnetism.