Strain tuning of the anomalous topological Hall effect at room temperature in bulk Mn₃Sn

The Weyl semimetal Mn₃Sn is a noncollinear antiferromagnet with a large intrinsic room temperature

anomalous Hall effect (AHE). While the anomalous topological Hall behavior arises from the inverse

triangular spin structure of the antiferromagnetic order, a small in-plane ferromagnetic component

allows weak (<0.5 T) magnetic fields to manipulate the anomalous Hall response. The easy controllability

of this large room temperature response makes this an exciting candidate material for

antiferromagnetic spintronic applications. In this work, we use in-situ tunable uniaxial stress to lower

the rotational symmetry of the crystallographic lattice. Paired with measurements of the evolution of

the AHE as a function of magnetic field angle, these experiments reveal the ability to induce an apparent

bias to the orientation of the ferromagnetic moment and lift the continuous rotation degeneracy of the

anomalous Hall state. Thus, we find that strain is an additional powerful control parameter to: (1)

seemingly bias the ferromagnetic poling direction and (2) change the magnitude of the AHE, which

depends sensitively on strain for specific magnetic field angles.