In 2022, physicists discovered altermagnets—a third type of magnetism that somehow combines the best qualities of the two previous types of magnetism. These unique magnets are difficult to identify, but a new proposal using quantum sensors might help make things easier. In a recent paper published in Physical Review Letters, physicists describe a theoretical technique that tracks the presence of an altermagnet by observing how it affects tiny magnetic defects in diamond. Altermagnets are known to have distinctive spin patterns, which can be traced back to how quickly diamond defects relax after being rotated. If current theories are correct, altermagnets could “completely revolutionize the way we transport information,” Jamir Marino, the study’s co-author and a physicist at the State University of New York at Buffalo, said in a statement. But first, we’ll need to see whether any of the 200+ materials suspected to be altermagnets truly do behave as predicted, the team added in the statement. Marino noted that the approach “could be the first building block of a new generation of experiments that determine whether a material is an altermagnet.”
The spins in a magnet The team behind the new study includes researchers involved in the original discovery of altermagnets. According to the statement, before this finding, researchers believed there were two main types of magnetism: ferromagnets and antiferromagnets. The former are the “classic” magnets, like stuff you stick on a fridge, whereas the latter refer to materials that display a complex magnetism at the atomic level.
