Pulse-width dependence of spin-orbit torque switching in Mn3Sn/Pt thin films

Spin-orbit torque (SOT) switching in chiral antiferromagnets, such as D0(19)-Mn3Sn, has opened prospects in antiferromagnetic spintronics. In this paper, we investigated the critical switching voltage as a function of the voltage pulse width in order to explore the thermal stability factor ? in the D0(19)-Mn3Sn. Although the critical switching voltage is found to decrease with increasing the voltage pulse width as expected by the thermally activated switching process with ? of 131.1 at 300 K, our detailed examinations reveal that the Joule heating due to the voltage pulse could induce the magnetic phase transition in the D0(19)-Mn3Sn, which significantly alters the energy landscape relevant to the SOT switching. This assisting mechanism for the SOT switching inhibits an accurate determination of ? but could deliver a smaller ? than the actual. Our study provides cautionary note in estimating the thermal stability of the chiral antiferromagnets.