We tend to think of magnets as binary. Batteries have positive and negative ends. Compasses point north and south. And, until late last year, there were two kinds of magnetism: ferromagnetism and antiferromagnetism.
Late in 2024, scientists discovered a third kind: altermagnetism. This class of magnetism — which has some characteristics of the other two — could greatly increase computer memory storage, and, in doing so, also save on both energy and rare earth materials. It could also boost the quest for superconductivity.
A New Kind of Magnetism
It was only a theoretical concept in 2019, after researchers at Johannes Gutenberg University Mainz (JGU) in Germany came across a result that couldn’t be explained by the two “legacy” types of magnetism. Experiments by the JGU group, with contributions from University of Nottingham researcher in England, and others, nailed down the third class as a legitimate form of magnetism in 2024. Subsequently more than 200 materials have been found to possess altermagnetic properties.
