Also known as magnetoelectronics, spintronics rely on electron spin rather than electron charge, as found in traditional electronics. Although spintronics is still an emerging field, spintronic technologies are already found in hard disk drives and giant magnetoresistance sensors used in industrial and automotive applications. Once the right foundational materials are discovered and verified, including economical materials for altermagnets, spintronics could advance technologies from wireless communication to quantum computing.

Researchers using neutrons at the Department of Energy’s Oak Ridge National Laboratory’s Spallation Neutron Source (SNS) discovered that hematite, essentially rust, can help design energy-efficient spintronics.

The team’s findings, published in Physical Review Letters, confirmed a key signature of altermagnetism (a new type of magnetism discovered in 2022) in hematite. Altermagnets are magnetic materials in which electron spins align in opposite directions, allowing pure spin currents to flow without a net electric charge—ideal conditions for spintronics. The team measured spin waves, which move through a material’s magnetic order similar to how sound waves move through air. They discovered that these waves show a clear separation in energy, a unique signature that confirms the material’s altermagnetic nature.