Altermagnetism Induced in Ruthenium Dioxide Ultrathin Films

Scientists have demonstrated that ruthenium dioxide, a material that is normally nonmagnetic, can exhibit a new form of magnetism when fabricated as an ultrathin film only a few atomic layers thick and subjected to mechanical strain. In this configuration, the electrons in the film arrange themselves in patterns that match the recently proposed altermagnetism state, a magnetic phase that differs from conventional ferromagnetism and antiferromagnetism. The experiment shows that strain engineering can activate altermagnetism in a material that otherwise lacks magnetic order, suggesting a route to integrate this exotic magnetic behavior into future electronic devices.