Altermagnets are a recently described class of materials that have no net magnetization but display magnetic-like electron behavior. Their unique properties could support advances in spintronics, which uses electron spin to develop faster, more efficient electronics. Because altermagnets do not produce stray magnetic fields, they could also allow devices to be placed closer together without interference.
“Ferromagnetism produces the behavior most people associate with everyday magnets,” said senior author University of Central Florida’s Professor Madhab Neupane and colleagues.
“In these materials, magnetic moments align in the same direction, creating a magnetic field. That property can be useful in electronics, but the resulting stray magnetic fields can interfere with nearby components.”
“Antiferromagnets behave differently. Their magnetic moments point in opposing directions and cancel one another out, largely avoiding the stray fields. However, they lack some of the useful electronic properties found in ferromagnets.”
“Altermagnets offer another possibility by combining desirable characteristics of both,” they added.
“Like antiferromagnets, they can avoid producing unwanted stray magnetic fields. But they can also generate and detect spin currents — the movement of electron spins through a material — that researchers hope to use for future electronics.”
In the study, the researchers used a technique called angle-resolved photoemission spectroscopy, which maps how electrons move inside a crystal, including measurements that distinguish between spin ‘up’ and spin ‘down’ electrons.
They first detected a characteristic splitting in the electronic bands of Co1/4TaSe2.
They then used spin-resolved angle-resolved photoemission spectroscopy to take a closer look and found that those split states carried opposite spin polarizations, key evidence of altermagnetism.
“The significance became clear once the experimental measurements consistently matched our theoretical predictions,” Professor Neupane said.
“Seeing those independent pieces of evidence converge gave us confidence that we had identified a genuine layered altermagnet.”
According to the scientists, the material is distinctive because it is a layered, van der Waals crystal, which could make it easier to combine with other exotic materials, such as superconductors, in layered devices.
Other altermagnet candidates studied so far, mainly manganese telluride and chromium antimonide, are not layered in this way.
“Evidence for altermagnetism in a versatile materials platform opens a lot of new possibilities,” said first author Milo Sprague, also from the University of Central Florida.
“There’s currently a lot of debate in altermagnetic theory about how the spin-polarized electronic states interact with other magnetic phenomena.”
“Now we have a material that we can easily modify to explore these new questions.”
For more information: Nature Communications
Image: Establishment of altermagnetic crystal and magnetic structure in Co1/4TaSe2. Image credit: Sprague et al., doi: 10.1038/s41467-026-76784-x.
