Altermagnetic materials

Altermagnets combine characteristics of both antiferromagnetism and ferromagnetic ordering. Here, the authors identify Co_1/4TaSe₂ as a layered altermagnetic material and show clear signatures of altermagnetic spin splitting at the Fermi surface.

Ruthenium dioxide is considered a candidate for metallic d-wave altermagnetism, but its magnetic ground state remains debated. Here, the authors use first-principles calculations to reveal that RuO₂ thin films cannot stabilize a compensated antiferromagnetic order, instead exhibiting ferrimagnetic-like behavior influenced by strain, orientation, and substrate effects, clarifying previous discrepancies.

CsCr3Sb5 is part of a family of Kagome materials noted for hosting a rich variety of emergent phases. Here, using scanning tunnelling microscopy and spectroscopy, Huang, Xu, Que, Liu and coauthors find two charge density wave orders, intertwined with a tuneable altermagnetic spin density wave order.

There are several examples of ferroelectric altermagnetic materials; however, it remains an active question as to whether an electric polarization can be induced by altermagnetic spin ordering. Here, Guo, Xu and coauthors demonstrate a link between the electric polarization vector and the altermagnetic Néel order parameter, which unambiguously realizes type-II multiferroicity.

The authors display a comprehensive study on the manipulation of topology and altermagnetism by controlling the hybridization of the surface states and the Fermi level of topological insulators.

The authors establish a universal symmetry framework that classifies spin–ferroelectric couplings in altermagnetic multiferroics into three fundamental types: decoupling, pseudo-time-reversal coupling, and asymmetric momentum mapping.

Altermagnets recently emerged as a new class of magnetic materials, arising from specific spin crystal symmetries. This paper studies a layered triangular lattice altermagnet, cobalt-intercalated NbSe2, using scanning tunneling microscopy and spectroscopy.