Ruthenium dioxide thin films exhibit altermagnetism, furnishing high density/ speed/ energy efficiency, in data storage for AI and data centers

https://www.eurekalert.org/news-releases/1110089

"0 net magnetization (like antiferromagnets) but with spin-split electronic structures (like ferromagnets), best of both: stable, high-density, easy to read electrically... poor sample quality overcome using sapphire substrates/ precise growth conditions to align all crystal axes... memory cells packed much closer together without interfering with each another since no stray magnetic fields... altermagnets inherently faster switching speeds than ferromagnets... future: discover other altermagnetic materials"

Related: Flat Fermi surface in altermagnets enables quantum limit spin currents
https://phys.org/news/2025-12-flat-fermi-surface-altermagnets-enables.html