Interplay of strain, magnetism, and topology: understanding electrical and thermal transport in a kagome antiferromagnet

Mn₃Sn, an antiferromagnetic Weyl semimetal, has garnered attention for its exotic magnetic properties. While its standard spin structure does not produce scalar spin chirality at room temperature, we show that in-plane anisotropic strain and the Dzyaloshinskii-Moriya interaction stabilize an out-of-plane canting of the Mn spins in Mn₃₋ₓSn₁₊ₓ epitaxial thin films, inducing scalar spin chirality. This leads to the observation of large anomalous Hall and Nernst effects at room temperature. Moreover, we observe the emergence of the topological Hall effect (THE) between 32 K and 300 K. The temperature-dependent behavior of the THE, along with supporting minor-loop measurements, suggests that the observed THE is driven by a nonzero scalar spin chirality-induced real-space Berry phase. These findings highlight the significant role of topological effects in Mn₃Sn, with implications for future spintronic devices.