Time-Dependent Multistate Switching of Topological Antiferromagnetic Order in Mn3Sn br

The manipulation of antiferromagnetic order by means of spin-orbit torques opens opportunities to exploit the dynamics of antiferromagnets in spintronic devices. In this work, we investigate the currentinduced switching of the magnetic octupole vector in the Weyl antiferromagnet Mn3Sn as a function of pulse shape, magnetic field, temperature, and time. We find that the switching behavior can be either bistable or tristable depending on the temporal structure of the current pulses. Time-resolved Hall effect measurements performed during the current pulsing reveal that Mn3Sn switching proceeds via a two-step demagnetization-remagnetization process caused by self-heating over a timescale of tens of nanoseconds followed by cooling in the presence of spin-orbit torques. Single-shot switching measurements with 50ps temporal resolution indicate that chiral spin rotation is either damped or incoherent in polycrystalline Mn3Sn. Our results shed light on the switching dynamics of Mn3Sn and prove the existence of extrinsic limits on its switching speed.