New approach to identifying altermagnetic materials

Magnetic materials have traditionally been classified as either ferromagnetic, like the decorative magnets on iron refrigerator doors that are seemingly always magnetic, or antiferromagnetic, like two bar magnets placed end-to-end with opposite poles facing each other, canceling each other out so that the material has no net magnetism. However, there appears to be a third class of magnetic materials exhibiting what in 2022 was dubbed altermagnetism.