Tuning the Hall response of a noncollinear antiferromagnet via spin-transfer torques and oscillating magnetic fields

Abstract: The kagome lattice antiferromagnets Mn$_3$X(= Sn, Ge) have a noncollinear 120$^\circ$ ordered ground state, which engenders a strong anomalous Hall response. It has been shown that this response is linked to the magnetic order and can be manipulated through it. Here we use a combination of strain and spin-transfer torques to control the magnetic order and hence switch deterministically between states of different chirality. Each of these chiral ground states has an anomalous Hall conductivity tensor in a different direction. Furthermore, we show that a similar manipulation of the strained sample can be obtained through oscillating magnetic fields, potentially opening a pathway to optical switching in these materials.