Elasto-Hall conductivity and the anomalous Hall effect in altermagnets

Altermagnets, in which time-reversal symmetry is broken but net magnetization is zero, have attracted much attention recently as a novel class of magnetic materials. Because the anomalous Hall effect (AHE) is only allowed for certain moment directions, it is not a generic property of altermagnets. Instead, the authors show here that a transport coefficient they call elasto-Hall conductivity, corresponding to a strain-induced AHE, can be used to directly probe the altermagnetic order parameter. Moreover, the elasto-Hall conductivity arises from the strain-induced deformation of the Berry curvature quadrupole that characterizes altermagnets.