Physicists at SLAC National Accelerator Laboratory say they have found conclusive evidence of a third kind of magnetism, a finding that upends a long-held assumption that magnetic materials fall into only two categories. The phenomenon, known as altermagnetism, has been the subject of theory for several years, but direct confirmation has been hard to obtain.
The team used specialized X-ray techniques that revealed a magnetic signature distinct from both ferromagnetism and antiferromagnetism, the two types familiar to physicists. That signature is what allowed the researchers to separate altermagnets from the materials they had previously been grouped with.
The significance of the result lies partly in the properties researchers expect these materials to have. Altermagnets may be able to carry information efficiently while remaining stable, which has drawn interest from those looking at computing and data storage. Potential applications mentioned in connection with the work include faster computers, more efficient data centers and quantum technologies.
Those applications remain speculative. Practical devices built from altermagnets have not yet been demonstrated, and the new confirmation establishes the existence of the material behavior rather than a route to a working product. Further research will be needed before any of the proposed uses can be assessed.