Controversy over the local magnetization magnitude in RuO2

Ascertain the true magnitude of the local magnetic moment in rutile RuO2 and resolve the controversy regarding the reported value of approximately 0.05 μB per Ru atom by reconciling experimental measurements with theoretical predictions for collinear antiparallel ordering and large altermagnetic spin splitting.

Background

RuO2 is a prototypical metallic altermagnet with predicted large spin splitting (~1.3 eV) and experimentally observed collinear antiparallel ordering at room temperature. Despite these findings, reported local magnetization values around 0.05 μB remain debated.

Resolving the magnitude and origin of the local moment is crucial for interpreting transport, optical, and dynamical phenomena in RuO2 and for benchmarking theories of altermagnetism against experiment.