Researchers at the University of Central Florida have found experimental evidence of altermagnetism, a newly recognized form of magnetism that could lead to faster and more energy-efficient electronics. This research is published in Nature Communications.
What is altermagnetism
Altermagnetism sits between two better-known types of magnetism. Ferromagnets have magnetic moments that point in the same direction, producing a magnetic field that can interfere with nearby electronics. Antiferromagnets have moments pointing in opposite directions that cancel out, eliminating stray fields but sacrificing useful electronic properties. Altermagnets combine the best of both: they avoid producing disruptive magnetic fields while still generating and detecting spin currents, which are essential for advanced electronics.
The UCF team identified altermagnetic signatures in Co₁/₄TaSe₂, a layered material from the transition-metal dichalcogenide (TMD) family. Magnetic cobalt atoms inserted between the layers create the material's unusual properties. The researchers used angle-resolved photoemission spectroscopy (ARPES), a technique that maps how electrons move through a material, to observe characteristic splitting in the electronic bands. Spin-resolved ARPES then confirmed that these split states carried opposite spin polarizations, the defining feature of altermagnetism.
This discovery matters because electronics makers are reaching the limits of conventional technology. Most current devices rely on electron charge to process information, but researchers are exploring spintronics, which uses electron spin instead. Spin currents can carry information without the heat and energy losses that plague charge-based circuits. Layered altermagnets like Co₁/₄TaSe₂ offer a thin, tunable platform for controlling electron spin without the magnetic interference that complicates device design.
The layered structure is particularly valuable because researchers can separate and restack the thin sheets, making the material highly adaptable for thin-film devices. Because the relevant electronic states originate within the material rather than just at the surface, Co₁/₄TaSe₂ provides a robust experimental system for studying altermagnetism and its interactions with other magnetic phenomena.