Electrical switching of the topological anomalous Hall effect in a non-collinear antiferromagnet above room temperature

TLDR: The anomalous Hall effect is allowed by symmetry in some non-collinear antiferromagnets and is associated with Bloch-band topological features as discussed by the authors, which is of interest in the development of low power electronic devices, but such devices are likely to demand electrical control over the effect.

Abstract: The anomalous Hall effect is allowed by symmetry in some non-collinear antiferromagnets and is associated with Bloch-band topological features. This topological anomalous Hall effect is of interest in the development of low-power electronic devices, but such devices are likely to demand electrical control over the effect. Here we report the observation of the anomalous Hall effect in high-quality thin films of the cubic non-collinear antiferromagnet Mn3Pt epitaxially grown on ferroelectric BaTiO3 substrates. We demonstrate that epitaxial strain can alter the anomalous Hall conductivity of the Mn3Pt films by more than an order of magnitude. Furthermore, we show that the anomalous Hall effect can be turned on and off by applying a small electric field to the BaTiO3 substrate when the heterostructure is at a temperature of around 360 K and the Mn3Pt is close to the phase transition between a low-temperature non-collinear antiferromagnetic state and a high-temperature collinear antiferromagnetic state. The switching effect is due to piezoelectric strain transferred from the BaTiO3 substrate to the Mn3Pt film by interfacial strain mediation.