Uniaxial Stress Enhanced Anisotropic Magnetoresistance and Superconductivity in the Kagome Superconductor LaRu ₃ Si ₂

To elucidate how kagome electronic structure governs quantum ground states, we introduce a unique approach combining in‐plane uniaxial stress tuning, magnetotransport, and first‐principles calculations to uncover its impact on superconducting and normal‐state properties in . We identify a pronounced anisotropy in both the upper critical field and the normal‐state magnetoresistance, indicating strong electronic anisotropy despite the three‐dimensional crystal structure. Furthermore, we find that the superconducting transition temperature increases under in‐plane stress applied within the kagome plane, although the enhancement is modest, reaching approximately 0.3 K at 0.6 GPa. Furthermore, the absolute magnetoresistance exhibits a pronounced increase from about 22 at zero stress to 35 at 0.6 GPa, indicating a substantial modification of the normal state above . The simultaneous enhancement of both and magnetoresistance under stress suggests a positive correlation between superconductivity and normal‐state electronic and magnetic properties in . Detailed calculations demonstrate that the stress‐induced evolution of superconductivity and magnetotransport arises from the cooperative interplay between modifications of the total density of states, kagome flat‐band physics, and anisotropic electronic response. In particular, the pronounced enhancement of magnetoresistance is closely linked to the stress‐driven downward shift of the Ru kagome‐derived flat band.