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

TL;DR

This paper demonstrates how strain, spin-transfer torques, and oscillating magnetic fields can control the magnetic order and anomalous Hall response in noncollinear antiferromagnets, enabling deterministic switching between different chiral states.

Contribution

It introduces a method to manipulate magnetic chirality and Hall response in kagome lattice antiferromagnets using strain, spin torques, and magnetic fields, including optical switching potential.

Findings

Deterministic switching between chiral magnetic states via strain and spin-transfer torques.

Different chiral states exhibit distinct anomalous Hall conductivity directions.

Oscillating magnetic fields can similarly manipulate magnetic order, suggesting optical control possibilities.

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.