Imprinting Electrically Switchable Scalar Spin Chirality by Anisotropic Strain in a Kagome Antiferromagnet.

Topological chiral antiferromagnets, such as Mn₃Sn, are emerging as promising materials for next-generation spintronic devices due to their intrinsic transport properties linked to exotic magnetic configurations. Here, it is demonstrated that anisotropic strain in Mn₃Sn thin films offers a novel approach to manipulate the magnetic ground state, unlocking new functionalities in this material. Anisotropic strain reduces the point group symmetry of the manganese (Mn) Kagome triangles from C_3v to C₁, significantly altering the energy landscape of the magnetic states in Mn₃Sn. This symmetry reduction enables even a tiny in-plane Dzyaloshinskii-Moriya (DM) interaction to induce canting of the Mn spins out of the Kagome plane. The modified magnetic ground state introduces a finite scalar spin chirality and results in a significant Berry phase in momentum space. Consequently, a large anomalous Hall effect emerges in the Kagome plane at room temperature - an effect that is absent in the bulk material. Moreover, this twofold degenerate magnetic state enables the creation of multiple-stable, non-volatile anomalous Hall resistance (AHR) memory states. These states are field-stable and can be controlled by thermal-assisted current-induced magnetization switching, requiring modest current densities and small bias fields, thereby offering a compelling new functionality in Mn₃Sn for spintronic applications.