Fig. 2: Electrical switching of the perpendicular magnetic octupole moment under bulk SOT in the chiral AFM order of Mn₃Sn.

a Schematic illustration of the SOT switching mechanisms in a noncollinear antiferromagnet and its twinned counterpart. In each case, the five subFigs from left to right highlight the evolution of spin configurations during the switching process, with the rightmost Fig denoting the final stable state. Under the spin–orbit torque, the sublattice spins (blue arrows) and the magnetic octupole moment (red arrows) exhibit opposite chiralities. The directions of the damping-like (DL) effective field acting on the sublattice spins and the octupole moment are indicated by green and purple arrows, respectively. b Schematic illustrating the switching of the cluster magnetic octupole of the chiral AFM order of Mn₃Sn by the SOT. Mn moments on the Kagome easy plane are shown by blue arrows. An electrical current j (purple arrow) flowing in the Pt layer generates a spin current whose polarization vector (red arrow) is perpendicular to the Kagome plane and induces the SOT on the Mn₃Sn layer. c BSOT switching behavior of sputtering-grown Pt/Mn₃Sn heterostructures on Al₂O₃ substrates with varying AFM thicknesses at room temperature. d R_H versus write current I of the Mn₃Sn/Pt heterostructure at room temperature. The bias magnetic field of −x0.05 T is applied along the j direction. e R_H versus write current I with 0.05 T bias magnetic field.