Rice University-led researchers found that ruthenium dioxide only a few atomic layers thick shows altermagnetic behavior when lattice strain is applied, with the results published in Science Advances.
Spin-resolved photoemission measurements and theoretical calculations showed the strained ultrathin film develops spin textures linked to unconventional magnetism, while bulk RuO2 has long been treated as nonmagnetic.
Lattice strain proved decisive: without it, electron spins in the ultrathin material behaved like those in bulk RuO2 and showed no sign of Altermagnetism.
The team said that strain-controlled magnetism could make RuO2 a tunable platform for denser, faster RAM and more efficient spintronic devices, supporting a late-2025 proposal for ultrathin RuO2 memory chips.