Mechanisms for stabilizing altermagnetism: applications to material candidates

Altermagnetism has been proposed as a new magnetic phase that has a vanishing net magnetization, like antiferromagnets, but shows time-reversal symmetry breaking, associated with ferromagnets. In this work, we study the 2D and 3D mechanisms giving rise to altermagnetism by examining the altermagnetic susceptibility and comparing it to the usual spin susceptibility. In particular, in the 2D case we study the effect of Van Hove singularities and propose a mechanism to stabilize altermagnetism. Finally, we discuss these findings in terms of relevant tight-binding models for altermagnetic materials candidates, including the rutile metal RuO2. We demonstrate that the minimal tight-binding models are sufficient to capture a leading altermagnetic instability.