Controlling Hall response in epitaxial Mn₃Sn thin films

Non-collinear antiferromagnet Mn₃Sn has been shown to exhibit large anomalous Hall effect at room temperature and is a promising material system for spintronics applications. However, so far anomalous Hall effect has only been observed with magnetic field lying within the Kagome plane. In this talk, I will show how anisotropic strain along with in-plane Dzyaloshinskii-Moria interaction arising from broken inversion symmetry at the heterointerfaces can imprint finite scalar spin chirality in Kagome lattices such as Mn₃Sn. The finite canting of the Mn spins out of the Kagome plane breaks both mirror and time-reversal symmetries that allows non-zero anomalous Hall conductivity with magnetic field applied perpendicular to the Kagome plane, which we observe in our epitaxial thin films. We also observe the appearance of topological Hall like signatures at lower temperatures, the stability of which can be controlled by varying the thickness of these thin films. I will show evidence for heat assisted switching of the anomalous Hall effect at room temperature and of the topological Hall like features by the application of electric pulse with modest current densities of ~1.5×10¹⁰ A/m². This allows us to access multiple-stable, non-volatile anomalous Hall resistance memory states, thereby adding a new functionality in this compound by thin film engineering.