Strained ultrathin ruthenium dioxide films reveal elusive altermagnetic behavior

In a study published in Science Advances, physicists Ming Yi, Bharat Jalan, Milan Radovic and collaborators reported that ruthenium dioxide, long considered non-magnetic in bulk, displays altermagnetic signatures when prepared as an epitaxially strained film only a few atomic layers thick. By probing the material’s spin texture with spin-resolved angle-resolved photoemission spectroscopy, they observed mirror-odd and mirror-even spin patterns consistent with the recently proposed altermagnetic phase.

The effect emerged only under lattice strain, indicating that mechanical deformation can act as a tuning knob for the magnetic order. The researchers argue that such strain-controlled altermagnetism could be valuable for next-generation spintronic and RAM technologies. The work was funded by the U.S. Department of Energy, the Gordon and Betty Moore Foundation’s EPiQS Initiative, and the Robert A. Welch Foundation.